3RNN/Lib/site-packages/pandas/tests/io/parser/test_parse_dates.py
2024-05-26 19:49:15 +02:00

2341 lines
68 KiB
Python

"""
Tests date parsing functionality for all of the
parsers defined in parsers.py
"""
from datetime import (
date,
datetime,
timedelta,
timezone,
)
from io import StringIO
from dateutil.parser import parse as du_parse
import numpy as np
import pytest
import pytz
from pandas._libs.tslibs import parsing
import pandas as pd
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
Series,
Timestamp,
)
import pandas._testing as tm
from pandas.core.indexes.datetimes import date_range
from pandas.core.tools.datetimes import start_caching_at
from pandas.io.parsers import read_csv
pytestmark = pytest.mark.filterwarnings(
"ignore:Passing a BlockManager to DataFrame:DeprecationWarning"
)
xfail_pyarrow = pytest.mark.usefixtures("pyarrow_xfail")
skip_pyarrow = pytest.mark.usefixtures("pyarrow_skip")
@xfail_pyarrow
def test_read_csv_with_custom_date_parser(all_parsers):
# GH36111
def __custom_date_parser(time):
time = time.astype(np.float64)
time = time.astype(int) # convert float seconds to int type
return pd.to_timedelta(time, unit="s")
testdata = StringIO(
"""time e n h
41047.00 -98573.7297 871458.0640 389.0089
41048.00 -98573.7299 871458.0640 389.0089
41049.00 -98573.7300 871458.0642 389.0088
41050.00 -98573.7299 871458.0643 389.0088
41051.00 -98573.7302 871458.0640 389.0086
"""
)
result = all_parsers.read_csv_check_warnings(
FutureWarning,
"Please use 'date_format' instead",
testdata,
delim_whitespace=True,
parse_dates=True,
date_parser=__custom_date_parser,
index_col="time",
)
time = [41047, 41048, 41049, 41050, 41051]
time = pd.TimedeltaIndex([pd.to_timedelta(i, unit="s") for i in time], name="time")
expected = DataFrame(
{
"e": [-98573.7297, -98573.7299, -98573.7300, -98573.7299, -98573.7302],
"n": [871458.0640, 871458.0640, 871458.0642, 871458.0643, 871458.0640],
"h": [389.0089, 389.0089, 389.0088, 389.0088, 389.0086],
},
index=time,
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
def test_read_csv_with_custom_date_parser_parse_dates_false(all_parsers):
# GH44366
def __custom_date_parser(time):
time = time.astype(np.float64)
time = time.astype(int) # convert float seconds to int type
return pd.to_timedelta(time, unit="s")
testdata = StringIO(
"""time e
41047.00 -93.77
41048.00 -95.79
41049.00 -98.73
41050.00 -93.99
41051.00 -97.72
"""
)
result = all_parsers.read_csv_check_warnings(
FutureWarning,
"Please use 'date_format' instead",
testdata,
delim_whitespace=True,
parse_dates=False,
date_parser=__custom_date_parser,
index_col="time",
)
time = Series([41047.00, 41048.00, 41049.00, 41050.00, 41051.00], name="time")
expected = DataFrame(
{"e": [-93.77, -95.79, -98.73, -93.99, -97.72]},
index=time,
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
def test_separator_date_conflict(all_parsers):
# Regression test for gh-4678
#
# Make sure thousands separator and
# date parsing do not conflict.
parser = all_parsers
data = "06-02-2013;13:00;1-000.215"
expected = DataFrame(
[[datetime(2013, 6, 2, 13, 0, 0), 1000.215]], columns=["Date", 2]
)
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
with tm.assert_produces_warning(
FutureWarning, match=depr_msg, check_stacklevel=False
):
df = parser.read_csv(
StringIO(data),
sep=";",
thousands="-",
parse_dates={"Date": [0, 1]},
header=None,
)
tm.assert_frame_equal(df, expected)
@pytest.mark.parametrize("keep_date_col", [True, False])
def test_multiple_date_col_custom(all_parsers, keep_date_col, request):
data = """\
KORD,19990127, 19:00:00, 18:56:00, 0.8100, 2.8100, 7.2000, 0.0000, 280.0000
KORD,19990127, 20:00:00, 19:56:00, 0.0100, 2.2100, 7.2000, 0.0000, 260.0000
KORD,19990127, 21:00:00, 20:56:00, -0.5900, 2.2100, 5.7000, 0.0000, 280.0000
KORD,19990127, 21:00:00, 21:18:00, -0.9900, 2.0100, 3.6000, 0.0000, 270.0000
KORD,19990127, 22:00:00, 21:56:00, -0.5900, 1.7100, 5.1000, 0.0000, 290.0000
KORD,19990127, 23:00:00, 22:56:00, -0.5900, 1.7100, 4.6000, 0.0000, 280.0000
"""
parser = all_parsers
if keep_date_col and parser.engine == "pyarrow":
# For this to pass, we need to disable auto-inference on the date columns
# in parse_dates. We have no way of doing this though
mark = pytest.mark.xfail(
reason="pyarrow doesn't support disabling auto-inference on column numbers."
)
request.applymarker(mark)
def date_parser(*date_cols):
"""
Test date parser.
Parameters
----------
date_cols : args
The list of data columns to parse.
Returns
-------
parsed : Series
"""
return parsing.try_parse_dates(
parsing.concat_date_cols(date_cols), parser=du_parse
)
kwds = {
"header": None,
"date_parser": date_parser,
"parse_dates": {"actual": [1, 2], "nominal": [1, 3]},
"keep_date_col": keep_date_col,
"names": ["X0", "X1", "X2", "X3", "X4", "X5", "X6", "X7", "X8"],
}
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
**kwds,
raise_on_extra_warnings=False,
)
expected = DataFrame(
[
[
datetime(1999, 1, 27, 19, 0),
datetime(1999, 1, 27, 18, 56),
"KORD",
"19990127",
" 19:00:00",
" 18:56:00",
0.81,
2.81,
7.2,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 20, 0),
datetime(1999, 1, 27, 19, 56),
"KORD",
"19990127",
" 20:00:00",
" 19:56:00",
0.01,
2.21,
7.2,
0.0,
260.0,
],
[
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 20, 56),
"KORD",
"19990127",
" 21:00:00",
" 20:56:00",
-0.59,
2.21,
5.7,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 21, 18),
"KORD",
"19990127",
" 21:00:00",
" 21:18:00",
-0.99,
2.01,
3.6,
0.0,
270.0,
],
[
datetime(1999, 1, 27, 22, 0),
datetime(1999, 1, 27, 21, 56),
"KORD",
"19990127",
" 22:00:00",
" 21:56:00",
-0.59,
1.71,
5.1,
0.0,
290.0,
],
[
datetime(1999, 1, 27, 23, 0),
datetime(1999, 1, 27, 22, 56),
"KORD",
"19990127",
" 23:00:00",
" 22:56:00",
-0.59,
1.71,
4.6,
0.0,
280.0,
],
],
columns=[
"actual",
"nominal",
"X0",
"X1",
"X2",
"X3",
"X4",
"X5",
"X6",
"X7",
"X8",
],
)
if not keep_date_col:
expected = expected.drop(["X1", "X2", "X3"], axis=1)
# Python can sometimes be flaky about how
# the aggregated columns are entered, so
# this standardizes the order.
result = result[expected.columns]
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize("container", [list, tuple, Index, Series])
@pytest.mark.parametrize("dim", [1, 2])
def test_concat_date_col_fail(container, dim):
msg = "not all elements from date_cols are numpy arrays"
value = "19990127"
date_cols = tuple(container([value]) for _ in range(dim))
with pytest.raises(ValueError, match=msg):
parsing.concat_date_cols(date_cols)
@pytest.mark.parametrize("keep_date_col", [True, False])
def test_multiple_date_col(all_parsers, keep_date_col, request):
data = """\
KORD,19990127, 19:00:00, 18:56:00, 0.8100, 2.8100, 7.2000, 0.0000, 280.0000
KORD,19990127, 20:00:00, 19:56:00, 0.0100, 2.2100, 7.2000, 0.0000, 260.0000
KORD,19990127, 21:00:00, 20:56:00, -0.5900, 2.2100, 5.7000, 0.0000, 280.0000
KORD,19990127, 21:00:00, 21:18:00, -0.9900, 2.0100, 3.6000, 0.0000, 270.0000
KORD,19990127, 22:00:00, 21:56:00, -0.5900, 1.7100, 5.1000, 0.0000, 290.0000
KORD,19990127, 23:00:00, 22:56:00, -0.5900, 1.7100, 4.6000, 0.0000, 280.0000
"""
parser = all_parsers
if keep_date_col and parser.engine == "pyarrow":
# For this to pass, we need to disable auto-inference on the date columns
# in parse_dates. We have no way of doing this though
mark = pytest.mark.xfail(
reason="pyarrow doesn't support disabling auto-inference on column numbers."
)
request.applymarker(mark)
depr_msg = "The 'keep_date_col' keyword in pd.read_csv is deprecated"
kwds = {
"header": None,
"parse_dates": [[1, 2], [1, 3]],
"keep_date_col": keep_date_col,
"names": ["X0", "X1", "X2", "X3", "X4", "X5", "X6", "X7", "X8"],
}
with tm.assert_produces_warning(
(DeprecationWarning, FutureWarning), match=depr_msg, check_stacklevel=False
):
result = parser.read_csv(StringIO(data), **kwds)
expected = DataFrame(
[
[
datetime(1999, 1, 27, 19, 0),
datetime(1999, 1, 27, 18, 56),
"KORD",
"19990127",
" 19:00:00",
" 18:56:00",
0.81,
2.81,
7.2,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 20, 0),
datetime(1999, 1, 27, 19, 56),
"KORD",
"19990127",
" 20:00:00",
" 19:56:00",
0.01,
2.21,
7.2,
0.0,
260.0,
],
[
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 20, 56),
"KORD",
"19990127",
" 21:00:00",
" 20:56:00",
-0.59,
2.21,
5.7,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 21, 18),
"KORD",
"19990127",
" 21:00:00",
" 21:18:00",
-0.99,
2.01,
3.6,
0.0,
270.0,
],
[
datetime(1999, 1, 27, 22, 0),
datetime(1999, 1, 27, 21, 56),
"KORD",
"19990127",
" 22:00:00",
" 21:56:00",
-0.59,
1.71,
5.1,
0.0,
290.0,
],
[
datetime(1999, 1, 27, 23, 0),
datetime(1999, 1, 27, 22, 56),
"KORD",
"19990127",
" 23:00:00",
" 22:56:00",
-0.59,
1.71,
4.6,
0.0,
280.0,
],
],
columns=[
"X1_X2",
"X1_X3",
"X0",
"X1",
"X2",
"X3",
"X4",
"X5",
"X6",
"X7",
"X8",
],
)
if not keep_date_col:
expected = expected.drop(["X1", "X2", "X3"], axis=1)
tm.assert_frame_equal(result, expected)
def test_date_col_as_index_col(all_parsers):
data = """\
KORD,19990127 19:00:00, 18:56:00, 0.8100, 2.8100, 7.2000, 0.0000, 280.0000
KORD,19990127 20:00:00, 19:56:00, 0.0100, 2.2100, 7.2000, 0.0000, 260.0000
KORD,19990127 21:00:00, 20:56:00, -0.5900, 2.2100, 5.7000, 0.0000, 280.0000
KORD,19990127 21:00:00, 21:18:00, -0.9900, 2.0100, 3.6000, 0.0000, 270.0000
KORD,19990127 22:00:00, 21:56:00, -0.5900, 1.7100, 5.1000, 0.0000, 290.0000
"""
parser = all_parsers
kwds = {
"header": None,
"parse_dates": [1],
"index_col": 1,
"names": ["X0", "X1", "X2", "X3", "X4", "X5", "X6", "X7"],
}
result = parser.read_csv(StringIO(data), **kwds)
index = Index(
[
datetime(1999, 1, 27, 19, 0),
datetime(1999, 1, 27, 20, 0),
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 22, 0),
],
name="X1",
)
expected = DataFrame(
[
["KORD", " 18:56:00", 0.81, 2.81, 7.2, 0.0, 280.0],
["KORD", " 19:56:00", 0.01, 2.21, 7.2, 0.0, 260.0],
["KORD", " 20:56:00", -0.59, 2.21, 5.7, 0.0, 280.0],
["KORD", " 21:18:00", -0.99, 2.01, 3.6, 0.0, 270.0],
["KORD", " 21:56:00", -0.59, 1.71, 5.1, 0.0, 290.0],
],
columns=["X0", "X2", "X3", "X4", "X5", "X6", "X7"],
index=index,
)
if parser.engine == "pyarrow":
# https://github.com/pandas-dev/pandas/issues/44231
# pyarrow 6.0 starts to infer time type
expected["X2"] = pd.to_datetime("1970-01-01" + expected["X2"]).dt.time
tm.assert_frame_equal(result, expected)
def test_multiple_date_cols_int_cast(all_parsers):
data = (
"KORD,19990127, 19:00:00, 18:56:00, 0.8100\n"
"KORD,19990127, 20:00:00, 19:56:00, 0.0100\n"
"KORD,19990127, 21:00:00, 20:56:00, -0.5900\n"
"KORD,19990127, 21:00:00, 21:18:00, -0.9900\n"
"KORD,19990127, 22:00:00, 21:56:00, -0.5900\n"
"KORD,19990127, 23:00:00, 22:56:00, -0.5900"
)
parse_dates = {"actual": [1, 2], "nominal": [1, 3]}
parser = all_parsers
kwds = {
"header": None,
"parse_dates": parse_dates,
"date_parser": pd.to_datetime,
}
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
**kwds,
raise_on_extra_warnings=False,
)
expected = DataFrame(
[
[datetime(1999, 1, 27, 19, 0), datetime(1999, 1, 27, 18, 56), "KORD", 0.81],
[datetime(1999, 1, 27, 20, 0), datetime(1999, 1, 27, 19, 56), "KORD", 0.01],
[
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 20, 56),
"KORD",
-0.59,
],
[
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 21, 18),
"KORD",
-0.99,
],
[
datetime(1999, 1, 27, 22, 0),
datetime(1999, 1, 27, 21, 56),
"KORD",
-0.59,
],
[
datetime(1999, 1, 27, 23, 0),
datetime(1999, 1, 27, 22, 56),
"KORD",
-0.59,
],
],
columns=["actual", "nominal", 0, 4],
)
# Python can sometimes be flaky about how
# the aggregated columns are entered, so
# this standardizes the order.
result = result[expected.columns]
tm.assert_frame_equal(result, expected)
def test_multiple_date_col_timestamp_parse(all_parsers):
parser = all_parsers
data = """05/31/2012,15:30:00.029,1306.25,1,E,0,,1306.25
05/31/2012,15:30:00.029,1306.25,8,E,0,,1306.25"""
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
parse_dates=[[0, 1]],
header=None,
date_parser=Timestamp,
raise_on_extra_warnings=False,
)
expected = DataFrame(
[
[
Timestamp("05/31/2012, 15:30:00.029"),
1306.25,
1,
"E",
0,
np.nan,
1306.25,
],
[
Timestamp("05/31/2012, 15:30:00.029"),
1306.25,
8,
"E",
0,
np.nan,
1306.25,
],
],
columns=["0_1", 2, 3, 4, 5, 6, 7],
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
def test_multiple_date_cols_with_header(all_parsers):
parser = all_parsers
data = """\
ID,date,NominalTime,ActualTime,TDew,TAir,Windspeed,Precip,WindDir
KORD,19990127, 19:00:00, 18:56:00, 0.8100, 2.8100, 7.2000, 0.0000, 280.0000
KORD,19990127, 20:00:00, 19:56:00, 0.0100, 2.2100, 7.2000, 0.0000, 260.0000
KORD,19990127, 21:00:00, 20:56:00, -0.5900, 2.2100, 5.7000, 0.0000, 280.0000
KORD,19990127, 21:00:00, 21:18:00, -0.9900, 2.0100, 3.6000, 0.0000, 270.0000
KORD,19990127, 22:00:00, 21:56:00, -0.5900, 1.7100, 5.1000, 0.0000, 290.0000
KORD,19990127, 23:00:00, 22:56:00, -0.5900, 1.7100, 4.6000, 0.0000, 280.0000"""
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
with tm.assert_produces_warning(
FutureWarning, match=depr_msg, check_stacklevel=False
):
result = parser.read_csv(StringIO(data), parse_dates={"nominal": [1, 2]})
expected = DataFrame(
[
[
datetime(1999, 1, 27, 19, 0),
"KORD",
" 18:56:00",
0.81,
2.81,
7.2,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 20, 0),
"KORD",
" 19:56:00",
0.01,
2.21,
7.2,
0.0,
260.0,
],
[
datetime(1999, 1, 27, 21, 0),
"KORD",
" 20:56:00",
-0.59,
2.21,
5.7,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 21, 0),
"KORD",
" 21:18:00",
-0.99,
2.01,
3.6,
0.0,
270.0,
],
[
datetime(1999, 1, 27, 22, 0),
"KORD",
" 21:56:00",
-0.59,
1.71,
5.1,
0.0,
290.0,
],
[
datetime(1999, 1, 27, 23, 0),
"KORD",
" 22:56:00",
-0.59,
1.71,
4.6,
0.0,
280.0,
],
],
columns=[
"nominal",
"ID",
"ActualTime",
"TDew",
"TAir",
"Windspeed",
"Precip",
"WindDir",
],
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"data,parse_dates,msg",
[
(
"""\
date_NominalTime,date,NominalTime
KORD1,19990127, 19:00:00
KORD2,19990127, 20:00:00""",
[[1, 2]],
("New date column already in dict date_NominalTime"),
),
(
"""\
ID,date,nominalTime
KORD,19990127, 19:00:00
KORD,19990127, 20:00:00""",
{"ID": [1, 2]},
"Date column ID already in dict",
),
],
)
def test_multiple_date_col_name_collision(all_parsers, data, parse_dates, msg):
parser = all_parsers
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
with pytest.raises(ValueError, match=msg):
with tm.assert_produces_warning(
(FutureWarning, DeprecationWarning), match=depr_msg, check_stacklevel=False
):
parser.read_csv(StringIO(data), parse_dates=parse_dates)
def test_date_parser_int_bug(all_parsers):
# see gh-3071
parser = all_parsers
data = (
"posix_timestamp,elapsed,sys,user,queries,query_time,rows,"
"accountid,userid,contactid,level,silo,method\n"
"1343103150,0.062353,0,4,6,0.01690,3,"
"12345,1,-1,3,invoice_InvoiceResource,search\n"
)
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
index_col=0,
parse_dates=[0],
# Note: we must pass tz and then drop the tz attribute
# (if we don't CI will flake out depending on the runner's local time)
date_parser=lambda x: datetime.fromtimestamp(int(x), tz=timezone.utc).replace(
tzinfo=None
),
raise_on_extra_warnings=False,
)
expected = DataFrame(
[
[
0.062353,
0,
4,
6,
0.01690,
3,
12345,
1,
-1,
3,
"invoice_InvoiceResource",
"search",
]
],
columns=[
"elapsed",
"sys",
"user",
"queries",
"query_time",
"rows",
"accountid",
"userid",
"contactid",
"level",
"silo",
"method",
],
index=Index([Timestamp("2012-07-24 04:12:30")], name="posix_timestamp"),
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
def test_nat_parse(all_parsers):
# see gh-3062
parser = all_parsers
df = DataFrame(
{
"A": np.arange(10, dtype="float64"),
"B": Timestamp("20010101").as_unit("ns"),
}
)
df.iloc[3:6, :] = np.nan
with tm.ensure_clean("__nat_parse_.csv") as path:
df.to_csv(path)
result = parser.read_csv(path, index_col=0, parse_dates=["B"])
tm.assert_frame_equal(result, df)
@skip_pyarrow
def test_csv_custom_parser(all_parsers):
data = """A,B,C
20090101,a,1,2
20090102,b,3,4
20090103,c,4,5
"""
parser = all_parsers
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
date_parser=lambda x: datetime.strptime(x, "%Y%m%d"),
)
expected = parser.read_csv(StringIO(data), parse_dates=True)
tm.assert_frame_equal(result, expected)
result = parser.read_csv(StringIO(data), date_format="%Y%m%d")
tm.assert_frame_equal(result, expected)
@skip_pyarrow
def test_parse_dates_implicit_first_col(all_parsers):
data = """A,B,C
20090101,a,1,2
20090102,b,3,4
20090103,c,4,5
"""
parser = all_parsers
result = parser.read_csv(StringIO(data), parse_dates=True)
expected = parser.read_csv(StringIO(data), index_col=0, parse_dates=True)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
def test_parse_dates_string(all_parsers):
data = """date,A,B,C
20090101,a,1,2
20090102,b,3,4
20090103,c,4,5
"""
parser = all_parsers
result = parser.read_csv(StringIO(data), index_col="date", parse_dates=["date"])
# freq doesn't round-trip
index = date_range("1/1/2009", periods=3, name="date")._with_freq(None)
expected = DataFrame(
{"A": ["a", "b", "c"], "B": [1, 3, 4], "C": [2, 4, 5]}, index=index
)
tm.assert_frame_equal(result, expected)
# Bug in https://github.com/dateutil/dateutil/issues/217
# has been addressed, but we just don't pass in the `yearfirst`
@pytest.mark.xfail(reason="yearfirst is not surfaced in read_*")
@pytest.mark.parametrize("parse_dates", [[["date", "time"]], [[0, 1]]])
def test_yy_format_with_year_first(all_parsers, parse_dates):
data = """date,time,B,C
090131,0010,1,2
090228,1020,3,4
090331,0830,5,6
"""
parser = all_parsers
result = parser.read_csv_check_warnings(
UserWarning,
"Could not infer format",
StringIO(data),
index_col=0,
parse_dates=parse_dates,
)
index = DatetimeIndex(
[
datetime(2009, 1, 31, 0, 10, 0),
datetime(2009, 2, 28, 10, 20, 0),
datetime(2009, 3, 31, 8, 30, 0),
],
dtype=object,
name="date_time",
)
expected = DataFrame({"B": [1, 3, 5], "C": [2, 4, 6]}, index=index)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
@pytest.mark.parametrize("parse_dates", [[0, 2], ["a", "c"]])
def test_parse_dates_column_list(all_parsers, parse_dates):
data = "a,b,c\n01/01/2010,1,15/02/2010"
parser = all_parsers
expected = DataFrame(
{"a": [datetime(2010, 1, 1)], "b": [1], "c": [datetime(2010, 2, 15)]}
)
expected = expected.set_index(["a", "b"])
result = parser.read_csv(
StringIO(data), index_col=[0, 1], parse_dates=parse_dates, dayfirst=True
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
@pytest.mark.parametrize("index_col", [[0, 1], [1, 0]])
def test_multi_index_parse_dates(all_parsers, index_col):
data = """index1,index2,A,B,C
20090101,one,a,1,2
20090101,two,b,3,4
20090101,three,c,4,5
20090102,one,a,1,2
20090102,two,b,3,4
20090102,three,c,4,5
20090103,one,a,1,2
20090103,two,b,3,4
20090103,three,c,4,5
"""
parser = all_parsers
index = MultiIndex.from_product(
[
(datetime(2009, 1, 1), datetime(2009, 1, 2), datetime(2009, 1, 3)),
("one", "two", "three"),
],
names=["index1", "index2"],
)
# Out of order.
if index_col == [1, 0]:
index = index.swaplevel(0, 1)
expected = DataFrame(
[
["a", 1, 2],
["b", 3, 4],
["c", 4, 5],
["a", 1, 2],
["b", 3, 4],
["c", 4, 5],
["a", 1, 2],
["b", 3, 4],
["c", 4, 5],
],
columns=["A", "B", "C"],
index=index,
)
result = parser.read_csv_check_warnings(
UserWarning,
"Could not infer format",
StringIO(data),
index_col=index_col,
parse_dates=True,
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
@pytest.mark.parametrize("kwargs", [{"dayfirst": True}, {"day_first": True}])
def test_parse_dates_custom_euro_format(all_parsers, kwargs):
parser = all_parsers
data = """foo,bar,baz
31/01/2010,1,2
01/02/2010,1,NA
02/02/2010,1,2
"""
if "dayfirst" in kwargs:
df = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
names=["time", "Q", "NTU"],
date_parser=lambda d: du_parse(d, **kwargs),
header=0,
index_col=0,
parse_dates=True,
na_values=["NA"],
)
exp_index = Index(
[datetime(2010, 1, 31), datetime(2010, 2, 1), datetime(2010, 2, 2)],
name="time",
)
expected = DataFrame(
{"Q": [1, 1, 1], "NTU": [2, np.nan, 2]},
index=exp_index,
columns=["Q", "NTU"],
)
tm.assert_frame_equal(df, expected)
else:
msg = "got an unexpected keyword argument 'day_first'"
with pytest.raises(TypeError, match=msg):
parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
names=["time", "Q", "NTU"],
date_parser=lambda d: du_parse(d, **kwargs),
skiprows=[0],
index_col=0,
parse_dates=True,
na_values=["NA"],
)
def test_parse_tz_aware(all_parsers):
# See gh-1693
parser = all_parsers
data = "Date,x\n2012-06-13T01:39:00Z,0.5"
result = parser.read_csv(StringIO(data), index_col=0, parse_dates=True)
# TODO: make unit check more specific
if parser.engine == "pyarrow":
result.index = result.index.as_unit("ns")
expected = DataFrame(
{"x": [0.5]}, index=Index([Timestamp("2012-06-13 01:39:00+00:00")], name="Date")
)
if parser.engine == "pyarrow":
expected_tz = pytz.utc
else:
expected_tz = timezone.utc
tm.assert_frame_equal(result, expected)
assert result.index.tz is expected_tz
@xfail_pyarrow
@pytest.mark.parametrize(
"parse_dates,index_col",
[({"nominal": [1, 2]}, "nominal"), ({"nominal": [1, 2]}, 0), ([[1, 2]], 0)],
)
def test_multiple_date_cols_index(all_parsers, parse_dates, index_col):
parser = all_parsers
data = """
ID,date,NominalTime,ActualTime,TDew,TAir,Windspeed,Precip,WindDir
KORD1,19990127, 19:00:00, 18:56:00, 0.8100, 2.8100, 7.2000, 0.0000, 280.0000
KORD2,19990127, 20:00:00, 19:56:00, 0.0100, 2.2100, 7.2000, 0.0000, 260.0000
KORD3,19990127, 21:00:00, 20:56:00, -0.5900, 2.2100, 5.7000, 0.0000, 280.0000
KORD4,19990127, 21:00:00, 21:18:00, -0.9900, 2.0100, 3.6000, 0.0000, 270.0000
KORD5,19990127, 22:00:00, 21:56:00, -0.5900, 1.7100, 5.1000, 0.0000, 290.0000
KORD6,19990127, 23:00:00, 22:56:00, -0.5900, 1.7100, 4.6000, 0.0000, 280.0000
"""
expected = DataFrame(
[
[
datetime(1999, 1, 27, 19, 0),
"KORD1",
" 18:56:00",
0.81,
2.81,
7.2,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 20, 0),
"KORD2",
" 19:56:00",
0.01,
2.21,
7.2,
0.0,
260.0,
],
[
datetime(1999, 1, 27, 21, 0),
"KORD3",
" 20:56:00",
-0.59,
2.21,
5.7,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 21, 0),
"KORD4",
" 21:18:00",
-0.99,
2.01,
3.6,
0.0,
270.0,
],
[
datetime(1999, 1, 27, 22, 0),
"KORD5",
" 21:56:00",
-0.59,
1.71,
5.1,
0.0,
290.0,
],
[
datetime(1999, 1, 27, 23, 0),
"KORD6",
" 22:56:00",
-0.59,
1.71,
4.6,
0.0,
280.0,
],
],
columns=[
"nominal",
"ID",
"ActualTime",
"TDew",
"TAir",
"Windspeed",
"Precip",
"WindDir",
],
)
expected = expected.set_index("nominal")
if not isinstance(parse_dates, dict):
expected.index.name = "date_NominalTime"
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
with tm.assert_produces_warning(
FutureWarning, match=depr_msg, check_stacklevel=False
):
result = parser.read_csv(
StringIO(data), parse_dates=parse_dates, index_col=index_col
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
def test_multiple_date_cols_chunked(all_parsers):
parser = all_parsers
data = """\
ID,date,nominalTime,actualTime,A,B,C,D,E
KORD,19990127, 19:00:00, 18:56:00, 0.8100, 2.8100, 7.2000, 0.0000, 280.0000
KORD,19990127, 20:00:00, 19:56:00, 0.0100, 2.2100, 7.2000, 0.0000, 260.0000
KORD,19990127, 21:00:00, 20:56:00, -0.5900, 2.2100, 5.7000, 0.0000, 280.0000
KORD,19990127, 21:00:00, 21:18:00, -0.9900, 2.0100, 3.6000, 0.0000, 270.0000
KORD,19990127, 22:00:00, 21:56:00, -0.5900, 1.7100, 5.1000, 0.0000, 290.0000
KORD,19990127, 23:00:00, 22:56:00, -0.5900, 1.7100, 4.6000, 0.0000, 280.0000
"""
expected = DataFrame(
[
[
datetime(1999, 1, 27, 19, 0),
"KORD",
" 18:56:00",
0.81,
2.81,
7.2,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 20, 0),
"KORD",
" 19:56:00",
0.01,
2.21,
7.2,
0.0,
260.0,
],
[
datetime(1999, 1, 27, 21, 0),
"KORD",
" 20:56:00",
-0.59,
2.21,
5.7,
0.0,
280.0,
],
[
datetime(1999, 1, 27, 21, 0),
"KORD",
" 21:18:00",
-0.99,
2.01,
3.6,
0.0,
270.0,
],
[
datetime(1999, 1, 27, 22, 0),
"KORD",
" 21:56:00",
-0.59,
1.71,
5.1,
0.0,
290.0,
],
[
datetime(1999, 1, 27, 23, 0),
"KORD",
" 22:56:00",
-0.59,
1.71,
4.6,
0.0,
280.0,
],
],
columns=["nominal", "ID", "actualTime", "A", "B", "C", "D", "E"],
)
expected = expected.set_index("nominal")
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
with tm.assert_produces_warning(
FutureWarning, match=depr_msg, check_stacklevel=False
):
with parser.read_csv(
StringIO(data),
parse_dates={"nominal": [1, 2]},
index_col="nominal",
chunksize=2,
) as reader:
chunks = list(reader)
tm.assert_frame_equal(chunks[0], expected[:2])
tm.assert_frame_equal(chunks[1], expected[2:4])
tm.assert_frame_equal(chunks[2], expected[4:])
def test_multiple_date_col_named_index_compat(all_parsers):
parser = all_parsers
data = """\
ID,date,nominalTime,actualTime,A,B,C,D,E
KORD,19990127, 19:00:00, 18:56:00, 0.8100, 2.8100, 7.2000, 0.0000, 280.0000
KORD,19990127, 20:00:00, 19:56:00, 0.0100, 2.2100, 7.2000, 0.0000, 260.0000
KORD,19990127, 21:00:00, 20:56:00, -0.5900, 2.2100, 5.7000, 0.0000, 280.0000
KORD,19990127, 21:00:00, 21:18:00, -0.9900, 2.0100, 3.6000, 0.0000, 270.0000
KORD,19990127, 22:00:00, 21:56:00, -0.5900, 1.7100, 5.1000, 0.0000, 290.0000
KORD,19990127, 23:00:00, 22:56:00, -0.5900, 1.7100, 4.6000, 0.0000, 280.0000
"""
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
with tm.assert_produces_warning(
(FutureWarning, DeprecationWarning), match=depr_msg, check_stacklevel=False
):
with_indices = parser.read_csv(
StringIO(data), parse_dates={"nominal": [1, 2]}, index_col="nominal"
)
with tm.assert_produces_warning(
(FutureWarning, DeprecationWarning), match=depr_msg, check_stacklevel=False
):
with_names = parser.read_csv(
StringIO(data),
index_col="nominal",
parse_dates={"nominal": ["date", "nominalTime"]},
)
tm.assert_frame_equal(with_indices, with_names)
def test_multiple_date_col_multiple_index_compat(all_parsers):
parser = all_parsers
data = """\
ID,date,nominalTime,actualTime,A,B,C,D,E
KORD,19990127, 19:00:00, 18:56:00, 0.8100, 2.8100, 7.2000, 0.0000, 280.0000
KORD,19990127, 20:00:00, 19:56:00, 0.0100, 2.2100, 7.2000, 0.0000, 260.0000
KORD,19990127, 21:00:00, 20:56:00, -0.5900, 2.2100, 5.7000, 0.0000, 280.0000
KORD,19990127, 21:00:00, 21:18:00, -0.9900, 2.0100, 3.6000, 0.0000, 270.0000
KORD,19990127, 22:00:00, 21:56:00, -0.5900, 1.7100, 5.1000, 0.0000, 290.0000
KORD,19990127, 23:00:00, 22:56:00, -0.5900, 1.7100, 4.6000, 0.0000, 280.0000
"""
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
with tm.assert_produces_warning(
(FutureWarning, DeprecationWarning), match=depr_msg, check_stacklevel=False
):
result = parser.read_csv(
StringIO(data), index_col=["nominal", "ID"], parse_dates={"nominal": [1, 2]}
)
with tm.assert_produces_warning(
(FutureWarning, DeprecationWarning), match=depr_msg, check_stacklevel=False
):
expected = parser.read_csv(StringIO(data), parse_dates={"nominal": [1, 2]})
expected = expected.set_index(["nominal", "ID"])
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize("kwargs", [{}, {"index_col": "C"}])
def test_read_with_parse_dates_scalar_non_bool(all_parsers, kwargs):
# see gh-5636
parser = all_parsers
msg = (
"Only booleans, lists, and dictionaries "
"are accepted for the 'parse_dates' parameter"
)
data = """A,B,C
1,2,2003-11-1"""
with pytest.raises(TypeError, match=msg):
parser.read_csv(StringIO(data), parse_dates="C", **kwargs)
@pytest.mark.parametrize("parse_dates", [(1,), np.array([4, 5]), {1, 3}])
def test_read_with_parse_dates_invalid_type(all_parsers, parse_dates):
parser = all_parsers
msg = (
"Only booleans, lists, and dictionaries "
"are accepted for the 'parse_dates' parameter"
)
data = """A,B,C
1,2,2003-11-1"""
with pytest.raises(TypeError, match=msg):
parser.read_csv(StringIO(data), parse_dates=(1,))
@pytest.mark.parametrize("cache_dates", [True, False])
@pytest.mark.parametrize("value", ["nan", ""])
def test_bad_date_parse(all_parsers, cache_dates, value):
# if we have an invalid date make sure that we handle this with
# and w/o the cache properly
parser = all_parsers
s = StringIO((f"{value},\n") * (start_caching_at + 1))
parser.read_csv(
s,
header=None,
names=["foo", "bar"],
parse_dates=["foo"],
cache_dates=cache_dates,
)
@pytest.mark.parametrize("cache_dates", [True, False])
@pytest.mark.parametrize("value", ["0"])
def test_bad_date_parse_with_warning(all_parsers, cache_dates, value):
# if we have an invalid date make sure that we handle this with
# and w/o the cache properly.
parser = all_parsers
s = StringIO((f"{value},\n") * 50000)
if parser.engine == "pyarrow":
# pyarrow reads "0" as 0 (of type int64), and so
# pandas doesn't try to guess the datetime format
# TODO: parse dates directly in pyarrow, see
# https://github.com/pandas-dev/pandas/issues/48017
warn = None
elif cache_dates:
# Note: warning is not raised if 'cache_dates', because here there is only a
# single unique date and hence no risk of inconsistent parsing.
warn = None
else:
warn = UserWarning
parser.read_csv_check_warnings(
warn,
"Could not infer format",
s,
header=None,
names=["foo", "bar"],
parse_dates=["foo"],
cache_dates=cache_dates,
raise_on_extra_warnings=False,
)
@xfail_pyarrow
def test_parse_dates_empty_string(all_parsers):
# see gh-2263
parser = all_parsers
data = "Date,test\n2012-01-01,1\n,2"
result = parser.read_csv(StringIO(data), parse_dates=["Date"], na_filter=False)
expected = DataFrame(
[[datetime(2012, 1, 1), 1], [pd.NaT, 2]], columns=["Date", "test"]
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"reader", ["read_csv_check_warnings", "read_table_check_warnings"]
)
def test_parse_dates_infer_datetime_format_warning(all_parsers, reader):
# GH 49024, 51017
parser = all_parsers
data = "Date,test\n2012-01-01,1\n,2"
getattr(parser, reader)(
FutureWarning,
"The argument 'infer_datetime_format' is deprecated",
StringIO(data),
parse_dates=["Date"],
infer_datetime_format=True,
sep=",",
raise_on_extra_warnings=False,
)
@pytest.mark.parametrize(
"reader", ["read_csv_check_warnings", "read_table_check_warnings"]
)
def test_parse_dates_date_parser_and_date_format(all_parsers, reader):
# GH 50601
parser = all_parsers
data = "Date,test\n2012-01-01,1\n,2"
msg = "Cannot use both 'date_parser' and 'date_format'"
with pytest.raises(TypeError, match=msg):
getattr(parser, reader)(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
parse_dates=["Date"],
date_parser=pd.to_datetime,
date_format="ISO8601",
sep=",",
)
@xfail_pyarrow
@pytest.mark.parametrize(
"data,kwargs,expected",
[
(
"a\n04.15.2016",
{"parse_dates": ["a"]},
DataFrame([datetime(2016, 4, 15)], columns=["a"]),
),
(
"a\n04.15.2016",
{"parse_dates": True, "index_col": 0},
DataFrame(index=DatetimeIndex(["2016-04-15"], name="a"), columns=[]),
),
(
"a,b\n04.15.2016,09.16.2013",
{"parse_dates": ["a", "b"]},
DataFrame(
[[datetime(2016, 4, 15), datetime(2013, 9, 16)]], columns=["a", "b"]
),
),
(
"a,b\n04.15.2016,09.16.2013",
{"parse_dates": True, "index_col": [0, 1]},
DataFrame(
index=MultiIndex.from_tuples(
[(datetime(2016, 4, 15), datetime(2013, 9, 16))], names=["a", "b"]
),
columns=[],
),
),
],
)
def test_parse_dates_no_convert_thousands(all_parsers, data, kwargs, expected):
# see gh-14066
parser = all_parsers
result = parser.read_csv(StringIO(data), thousands=".", **kwargs)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
def test_parse_date_time_multi_level_column_name(all_parsers):
data = """\
D,T,A,B
date, time,a,b
2001-01-05, 09:00:00, 0.0, 10.
2001-01-06, 00:00:00, 1.0, 11.
"""
parser = all_parsers
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
header=[0, 1],
parse_dates={"date_time": [0, 1]},
date_parser=pd.to_datetime,
)
expected_data = [
[datetime(2001, 1, 5, 9, 0, 0), 0.0, 10.0],
[datetime(2001, 1, 6, 0, 0, 0), 1.0, 11.0],
]
expected = DataFrame(expected_data, columns=["date_time", ("A", "a"), ("B", "b")])
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"data,kwargs,expected",
[
(
"""\
date,time,a,b
2001-01-05, 10:00:00, 0.0, 10.
2001-01-05, 00:00:00, 1., 11.
""",
{"header": 0, "parse_dates": {"date_time": [0, 1]}},
DataFrame(
[
[datetime(2001, 1, 5, 10, 0, 0), 0.0, 10],
[datetime(2001, 1, 5, 0, 0, 0), 1.0, 11.0],
],
columns=["date_time", "a", "b"],
),
),
(
(
"KORD,19990127, 19:00:00, 18:56:00, 0.8100\n"
"KORD,19990127, 20:00:00, 19:56:00, 0.0100\n"
"KORD,19990127, 21:00:00, 20:56:00, -0.5900\n"
"KORD,19990127, 21:00:00, 21:18:00, -0.9900\n"
"KORD,19990127, 22:00:00, 21:56:00, -0.5900\n"
"KORD,19990127, 23:00:00, 22:56:00, -0.5900"
),
{"header": None, "parse_dates": {"actual": [1, 2], "nominal": [1, 3]}},
DataFrame(
[
[
datetime(1999, 1, 27, 19, 0),
datetime(1999, 1, 27, 18, 56),
"KORD",
0.81,
],
[
datetime(1999, 1, 27, 20, 0),
datetime(1999, 1, 27, 19, 56),
"KORD",
0.01,
],
[
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 20, 56),
"KORD",
-0.59,
],
[
datetime(1999, 1, 27, 21, 0),
datetime(1999, 1, 27, 21, 18),
"KORD",
-0.99,
],
[
datetime(1999, 1, 27, 22, 0),
datetime(1999, 1, 27, 21, 56),
"KORD",
-0.59,
],
[
datetime(1999, 1, 27, 23, 0),
datetime(1999, 1, 27, 22, 56),
"KORD",
-0.59,
],
],
columns=["actual", "nominal", 0, 4],
),
),
],
)
def test_parse_date_time(all_parsers, data, kwargs, expected):
parser = all_parsers
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
date_parser=pd.to_datetime,
**kwargs,
raise_on_extra_warnings=False,
)
# Python can sometimes be flaky about how
# the aggregated columns are entered, so
# this standardizes the order.
result = result[expected.columns]
tm.assert_frame_equal(result, expected)
def test_parse_date_fields(all_parsers):
parser = all_parsers
data = "year,month,day,a\n2001,01,10,10.\n2001,02,1,11."
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
header=0,
parse_dates={"ymd": [0, 1, 2]},
date_parser=lambda x: x,
raise_on_extra_warnings=False,
)
expected = DataFrame(
[[datetime(2001, 1, 10), 10.0], [datetime(2001, 2, 1), 11.0]],
columns=["ymd", "a"],
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
("key", "value", "warn"),
[
(
"date_parser",
lambda x: pd.to_datetime(x, format="%Y %m %d %H %M %S"),
FutureWarning,
),
("date_format", "%Y %m %d %H %M %S", None),
],
)
def test_parse_date_all_fields(all_parsers, key, value, warn):
parser = all_parsers
data = """\
year,month,day,hour,minute,second,a,b
2001,01,05,10,00,0,0.0,10.
2001,01,5,10,0,00,1.,11.
"""
result = parser.read_csv_check_warnings(
warn,
"use 'date_format' instead",
StringIO(data),
header=0,
parse_dates={"ymdHMS": [0, 1, 2, 3, 4, 5]},
**{key: value},
raise_on_extra_warnings=False,
)
expected = DataFrame(
[
[datetime(2001, 1, 5, 10, 0, 0), 0.0, 10.0],
[datetime(2001, 1, 5, 10, 0, 0), 1.0, 11.0],
],
columns=["ymdHMS", "a", "b"],
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
("key", "value", "warn"),
[
(
"date_parser",
lambda x: pd.to_datetime(x, format="%Y %m %d %H %M %S.%f"),
FutureWarning,
),
("date_format", "%Y %m %d %H %M %S.%f", None),
],
)
def test_datetime_fractional_seconds(all_parsers, key, value, warn):
parser = all_parsers
data = """\
year,month,day,hour,minute,second,a,b
2001,01,05,10,00,0.123456,0.0,10.
2001,01,5,10,0,0.500000,1.,11.
"""
result = parser.read_csv_check_warnings(
warn,
"use 'date_format' instead",
StringIO(data),
header=0,
parse_dates={"ymdHMS": [0, 1, 2, 3, 4, 5]},
**{key: value},
raise_on_extra_warnings=False,
)
expected = DataFrame(
[
[datetime(2001, 1, 5, 10, 0, 0, microsecond=123456), 0.0, 10.0],
[datetime(2001, 1, 5, 10, 0, 0, microsecond=500000), 1.0, 11.0],
],
columns=["ymdHMS", "a", "b"],
)
tm.assert_frame_equal(result, expected)
def test_generic(all_parsers):
parser = all_parsers
data = "year,month,day,a\n2001,01,10,10.\n2001,02,1,11."
def parse_function(yy, mm):
return [date(year=int(y), month=int(m), day=1) for y, m in zip(yy, mm)]
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
header=0,
parse_dates={"ym": [0, 1]},
date_parser=parse_function,
raise_on_extra_warnings=False,
)
expected = DataFrame(
[[date(2001, 1, 1), 10, 10.0], [date(2001, 2, 1), 1, 11.0]],
columns=["ym", "day", "a"],
)
expected["ym"] = expected["ym"].astype("datetime64[ns]")
tm.assert_frame_equal(result, expected)
@xfail_pyarrow
def test_date_parser_resolution_if_not_ns(all_parsers):
# see gh-10245
parser = all_parsers
data = """\
date,time,prn,rxstatus
2013-11-03,19:00:00,126,00E80000
2013-11-03,19:00:00,23,00E80000
2013-11-03,19:00:00,13,00E80000
"""
def date_parser(dt, time):
try:
arr = dt + "T" + time
except TypeError:
# dt & time are date/time objects
arr = [datetime.combine(d, t) for d, t in zip(dt, time)]
return np.array(arr, dtype="datetime64[s]")
result = parser.read_csv_check_warnings(
FutureWarning,
"use 'date_format' instead",
StringIO(data),
date_parser=date_parser,
parse_dates={"datetime": ["date", "time"]},
index_col=["datetime", "prn"],
)
datetimes = np.array(["2013-11-03T19:00:00"] * 3, dtype="datetime64[s]")
expected = DataFrame(
data={"rxstatus": ["00E80000"] * 3},
index=MultiIndex.from_arrays(
[datetimes, [126, 23, 13]],
names=["datetime", "prn"],
),
)
tm.assert_frame_equal(result, expected)
def test_parse_date_column_with_empty_string(all_parsers):
# see gh-6428
parser = all_parsers
data = "case,opdate\n7,10/18/2006\n7,10/18/2008\n621, "
result = parser.read_csv(StringIO(data), parse_dates=["opdate"])
expected_data = [[7, "10/18/2006"], [7, "10/18/2008"], [621, " "]]
expected = DataFrame(expected_data, columns=["case", "opdate"])
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"data,expected",
[
(
"a\n135217135789158401\n1352171357E+5",
DataFrame({"a": [135217135789158401, 135217135700000]}, dtype="float64"),
),
(
"a\n99999999999\n123456789012345\n1234E+0",
DataFrame({"a": [99999999999, 123456789012345, 1234]}, dtype="float64"),
),
],
)
@pytest.mark.parametrize("parse_dates", [True, False])
def test_parse_date_float(all_parsers, data, expected, parse_dates):
# see gh-2697
#
# Date parsing should fail, so we leave the data untouched
# (i.e. float precision should remain unchanged).
parser = all_parsers
result = parser.read_csv(StringIO(data), parse_dates=parse_dates)
tm.assert_frame_equal(result, expected)
def test_parse_timezone(all_parsers):
# see gh-22256
parser = all_parsers
data = """dt,val
2018-01-04 09:01:00+09:00,23350
2018-01-04 09:02:00+09:00,23400
2018-01-04 09:03:00+09:00,23400
2018-01-04 09:04:00+09:00,23400
2018-01-04 09:05:00+09:00,23400"""
result = parser.read_csv(StringIO(data), parse_dates=["dt"])
dti = date_range(
start="2018-01-04 09:01:00",
end="2018-01-04 09:05:00",
freq="1min",
tz=timezone(timedelta(minutes=540)),
)._with_freq(None)
expected_data = {"dt": dti, "val": [23350, 23400, 23400, 23400, 23400]}
expected = DataFrame(expected_data)
tm.assert_frame_equal(result, expected)
@skip_pyarrow # pandas.errors.ParserError: CSV parse error
@pytest.mark.parametrize(
"date_string",
["32/32/2019", "02/30/2019", "13/13/2019", "13/2019", "a3/11/2018", "10/11/2o17"],
)
def test_invalid_parse_delimited_date(all_parsers, date_string):
parser = all_parsers
expected = DataFrame({0: [date_string]}, dtype="object")
result = parser.read_csv(
StringIO(date_string),
header=None,
parse_dates=[0],
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"date_string,dayfirst,expected",
[
# %d/%m/%Y; month > 12 thus replacement
("13/02/2019", True, datetime(2019, 2, 13)),
# %m/%d/%Y; day > 12 thus there will be no replacement
("02/13/2019", False, datetime(2019, 2, 13)),
# %d/%m/%Y; dayfirst==True thus replacement
("04/02/2019", True, datetime(2019, 2, 4)),
],
)
def test_parse_delimited_date_swap_no_warning(
all_parsers, date_string, dayfirst, expected, request
):
parser = all_parsers
expected = DataFrame({0: [expected]}, dtype="datetime64[ns]")
if parser.engine == "pyarrow":
if not dayfirst:
# "CSV parse error: Empty CSV file or block"
pytest.skip(reason="https://github.com/apache/arrow/issues/38676")
msg = "The 'dayfirst' option is not supported with the 'pyarrow' engine"
with pytest.raises(ValueError, match=msg):
parser.read_csv(
StringIO(date_string), header=None, dayfirst=dayfirst, parse_dates=[0]
)
return
result = parser.read_csv(
StringIO(date_string), header=None, dayfirst=dayfirst, parse_dates=[0]
)
tm.assert_frame_equal(result, expected)
# ArrowInvalid: CSV parse error: Empty CSV file or block: cannot infer number of columns
@skip_pyarrow
@pytest.mark.parametrize(
"date_string,dayfirst,expected",
[
# %d/%m/%Y; month > 12
("13/02/2019", False, datetime(2019, 2, 13)),
# %m/%d/%Y; day > 12
("02/13/2019", True, datetime(2019, 2, 13)),
],
)
def test_parse_delimited_date_swap_with_warning(
all_parsers, date_string, dayfirst, expected
):
parser = all_parsers
expected = DataFrame({0: [expected]}, dtype="datetime64[ns]")
warning_msg = (
"Parsing dates in .* format when dayfirst=.* was specified. "
"Pass `dayfirst=.*` or specify a format to silence this warning."
)
result = parser.read_csv_check_warnings(
UserWarning,
warning_msg,
StringIO(date_string),
header=None,
dayfirst=dayfirst,
parse_dates=[0],
)
tm.assert_frame_equal(result, expected)
def test_parse_multiple_delimited_dates_with_swap_warnings():
# GH46210
with pytest.raises(
ValueError,
match=(
r'^time data "31/05/2000" doesn\'t match format "%m/%d/%Y", '
r"at position 1. You might want to try:"
),
):
pd.to_datetime(["01/01/2000", "31/05/2000", "31/05/2001", "01/02/2000"])
# ArrowKeyError: Column 'fdate1' in include_columns does not exist in CSV file
@skip_pyarrow
@pytest.mark.parametrize(
"names, usecols, parse_dates, missing_cols",
[
(None, ["val"], ["date", "time"], "date, time"),
(None, ["val"], [0, "time"], "time"),
(None, ["val"], [["date", "time"]], "date, time"),
(None, ["val"], [[0, "time"]], "time"),
(None, ["val"], {"date": [0, "time"]}, "time"),
(None, ["val"], {"date": ["date", "time"]}, "date, time"),
(None, ["val"], [["date", "time"], "date"], "date, time"),
(["date1", "time1", "temperature"], None, ["date", "time"], "date, time"),
(
["date1", "time1", "temperature"],
["date1", "temperature"],
["date1", "time"],
"time",
),
],
)
def test_missing_parse_dates_column_raises(
all_parsers, names, usecols, parse_dates, missing_cols
):
# gh-31251 column names provided in parse_dates could be missing.
parser = all_parsers
content = StringIO("date,time,val\n2020-01-31,04:20:32,32\n")
msg = f"Missing column provided to 'parse_dates': '{missing_cols}'"
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
warn = FutureWarning
if isinstance(parse_dates, list) and all(
isinstance(x, (int, str)) for x in parse_dates
):
warn = None
with pytest.raises(ValueError, match=msg):
with tm.assert_produces_warning(warn, match=depr_msg, check_stacklevel=False):
parser.read_csv(
content, sep=",", names=names, usecols=usecols, parse_dates=parse_dates
)
@xfail_pyarrow # mismatched shape
def test_date_parser_and_names(all_parsers):
# GH#33699
parser = all_parsers
data = StringIO("""x,y\n1,2""")
warn = UserWarning
if parser.engine == "pyarrow":
# DeprecationWarning for passing a Manager object
warn = (UserWarning, DeprecationWarning)
result = parser.read_csv_check_warnings(
warn,
"Could not infer format",
data,
parse_dates=["B"],
names=["B"],
)
expected = DataFrame({"B": ["y", "2"]}, index=["x", "1"])
tm.assert_frame_equal(result, expected)
@xfail_pyarrow # TypeError: an integer is required
def test_date_parser_multiindex_columns(all_parsers):
parser = all_parsers
data = """a,b
1,2
2019-12-31,6"""
result = parser.read_csv(StringIO(data), parse_dates=[("a", "1")], header=[0, 1])
expected = DataFrame(
{("a", "1"): Timestamp("2019-12-31").as_unit("ns"), ("b", "2"): [6]}
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow # TypeError: an integer is required
@pytest.mark.parametrize(
"parse_spec, col_name",
[
([[("a", "1"), ("b", "2")]], ("a_b", "1_2")),
({("foo", "1"): [("a", "1"), ("b", "2")]}, ("foo", "1")),
],
)
def test_date_parser_multiindex_columns_combine_cols(all_parsers, parse_spec, col_name):
parser = all_parsers
data = """a,b,c
1,2,3
2019-12,-31,6"""
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
with tm.assert_produces_warning(
FutureWarning, match=depr_msg, check_stacklevel=False
):
result = parser.read_csv(
StringIO(data),
parse_dates=parse_spec,
header=[0, 1],
)
expected = DataFrame(
{col_name: Timestamp("2019-12-31").as_unit("ns"), ("c", "3"): [6]}
)
tm.assert_frame_equal(result, expected)
def test_date_parser_usecols_thousands(all_parsers):
# GH#39365
data = """A,B,C
1,3,20-09-01-01
2,4,20-09-01-01
"""
parser = all_parsers
if parser.engine == "pyarrow":
# DeprecationWarning for passing a Manager object
msg = "The 'thousands' option is not supported with the 'pyarrow' engine"
with pytest.raises(ValueError, match=msg):
parser.read_csv(
StringIO(data),
parse_dates=[1],
usecols=[1, 2],
thousands="-",
)
return
result = parser.read_csv_check_warnings(
UserWarning,
"Could not infer format",
StringIO(data),
parse_dates=[1],
usecols=[1, 2],
thousands="-",
)
expected = DataFrame({"B": [3, 4], "C": [Timestamp("20-09-2001 01:00:00")] * 2})
tm.assert_frame_equal(result, expected)
@xfail_pyarrow # mismatched shape
def test_parse_dates_and_keep_original_column(all_parsers):
# GH#13378
parser = all_parsers
data = """A
20150908
20150909
"""
depr_msg = "The 'keep_date_col' keyword in pd.read_csv is deprecated"
with tm.assert_produces_warning(
FutureWarning, match=depr_msg, check_stacklevel=False
):
result = parser.read_csv(
StringIO(data), parse_dates={"date": ["A"]}, keep_date_col=True
)
expected_data = [Timestamp("2015-09-08"), Timestamp("2015-09-09")]
expected = DataFrame({"date": expected_data, "A": expected_data})
tm.assert_frame_equal(result, expected)
def test_dayfirst_warnings():
# GH 12585
# CASE 1: valid input
input = "date\n31/12/2014\n10/03/2011"
expected = DatetimeIndex(
["2014-12-31", "2011-03-10"], dtype="datetime64[ns]", freq=None, name="date"
)
warning_msg = (
"Parsing dates in .* format when dayfirst=.* was specified. "
"Pass `dayfirst=.*` or specify a format to silence this warning."
)
# A. dayfirst arg correct, no warning
res1 = read_csv(
StringIO(input), parse_dates=["date"], dayfirst=True, index_col="date"
).index
tm.assert_index_equal(expected, res1)
# B. dayfirst arg incorrect, warning
with tm.assert_produces_warning(UserWarning, match=warning_msg):
res2 = read_csv(
StringIO(input), parse_dates=["date"], dayfirst=False, index_col="date"
).index
tm.assert_index_equal(expected, res2)
# CASE 2: invalid input
# cannot consistently process with single format
# return to user unaltered
# first in DD/MM/YYYY, second in MM/DD/YYYY
input = "date\n31/12/2014\n03/30/2011"
expected = Index(["31/12/2014", "03/30/2011"], dtype="object", name="date")
# A. use dayfirst=True
res5 = read_csv(
StringIO(input), parse_dates=["date"], dayfirst=True, index_col="date"
).index
tm.assert_index_equal(expected, res5)
# B. use dayfirst=False
with tm.assert_produces_warning(UserWarning, match=warning_msg):
res6 = read_csv(
StringIO(input), parse_dates=["date"], dayfirst=False, index_col="date"
).index
tm.assert_index_equal(expected, res6)
@pytest.mark.parametrize(
"date_string, dayfirst",
[
pytest.param(
"31/1/2014",
False,
id="second date is single-digit",
),
pytest.param(
"1/31/2014",
True,
id="first date is single-digit",
),
],
)
def test_dayfirst_warnings_no_leading_zero(date_string, dayfirst):
# GH47880
initial_value = f"date\n{date_string}"
expected = DatetimeIndex(
["2014-01-31"], dtype="datetime64[ns]", freq=None, name="date"
)
warning_msg = (
"Parsing dates in .* format when dayfirst=.* was specified. "
"Pass `dayfirst=.*` or specify a format to silence this warning."
)
with tm.assert_produces_warning(UserWarning, match=warning_msg):
res = read_csv(
StringIO(initial_value),
parse_dates=["date"],
index_col="date",
dayfirst=dayfirst,
).index
tm.assert_index_equal(expected, res)
@skip_pyarrow # CSV parse error: Expected 3 columns, got 4
def test_infer_first_column_as_index(all_parsers):
# GH#11019
parser = all_parsers
data = "a,b,c\n1970-01-01,2,3,4"
result = parser.read_csv(
StringIO(data),
parse_dates=["a"],
)
expected = DataFrame({"a": "2", "b": 3, "c": 4}, index=["1970-01-01"])
tm.assert_frame_equal(result, expected)
@xfail_pyarrow # pyarrow engine doesn't support passing a dict for na_values
@pytest.mark.parametrize(
("key", "value", "warn"),
[
("date_parser", lambda x: pd.to_datetime(x, format="%Y-%m-%d"), FutureWarning),
("date_format", "%Y-%m-%d", None),
],
)
def test_replace_nans_before_parsing_dates(all_parsers, key, value, warn):
# GH#26203
parser = all_parsers
data = """Test
2012-10-01
0
2015-05-15
#
2017-09-09
"""
result = parser.read_csv_check_warnings(
warn,
"use 'date_format' instead",
StringIO(data),
na_values={"Test": ["#", "0"]},
parse_dates=["Test"],
**{key: value},
)
expected = DataFrame(
{
"Test": [
Timestamp("2012-10-01"),
pd.NaT,
Timestamp("2015-05-15"),
pd.NaT,
Timestamp("2017-09-09"),
]
}
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow # string[python] instead of dt64[ns]
def test_parse_dates_and_string_dtype(all_parsers):
# GH#34066
parser = all_parsers
data = """a,b
1,2019-12-31
"""
result = parser.read_csv(StringIO(data), dtype="string", parse_dates=["b"])
expected = DataFrame({"a": ["1"], "b": [Timestamp("2019-12-31")]})
expected["a"] = expected["a"].astype("string")
tm.assert_frame_equal(result, expected)
def test_parse_dot_separated_dates(all_parsers):
# https://github.com/pandas-dev/pandas/issues/2586
parser = all_parsers
data = """a,b
27.03.2003 14:55:00.000,1
03.08.2003 15:20:00.000,2"""
if parser.engine == "pyarrow":
expected_index = Index(
["27.03.2003 14:55:00.000", "03.08.2003 15:20:00.000"],
dtype="object",
name="a",
)
warn = None
else:
expected_index = DatetimeIndex(
["2003-03-27 14:55:00", "2003-08-03 15:20:00"],
dtype="datetime64[ns]",
name="a",
)
warn = UserWarning
msg = r"when dayfirst=False \(the default\) was specified"
result = parser.read_csv_check_warnings(
warn,
msg,
StringIO(data),
parse_dates=True,
index_col=0,
raise_on_extra_warnings=False,
)
expected = DataFrame({"b": [1, 2]}, index=expected_index)
tm.assert_frame_equal(result, expected)
def test_parse_dates_dict_format(all_parsers):
# GH#51240
parser = all_parsers
data = """a,b
2019-12-31,31-12-2019
2020-12-31,31-12-2020"""
result = parser.read_csv(
StringIO(data),
date_format={"a": "%Y-%m-%d", "b": "%d-%m-%Y"},
parse_dates=["a", "b"],
)
expected = DataFrame(
{
"a": [Timestamp("2019-12-31"), Timestamp("2020-12-31")],
"b": [Timestamp("2019-12-31"), Timestamp("2020-12-31")],
}
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"key, parse_dates", [("a_b", [[0, 1]]), ("foo", {"foo": [0, 1]})]
)
def test_parse_dates_dict_format_two_columns(all_parsers, key, parse_dates):
# GH#51240
parser = all_parsers
data = """a,b
31-,12-2019
31-,12-2020"""
depr_msg = (
"Support for nested sequences for 'parse_dates' in pd.read_csv is deprecated"
)
with tm.assert_produces_warning(
(FutureWarning, DeprecationWarning), match=depr_msg, check_stacklevel=False
):
result = parser.read_csv(
StringIO(data), date_format={key: "%d- %m-%Y"}, parse_dates=parse_dates
)
expected = DataFrame(
{
key: [Timestamp("2019-12-31"), Timestamp("2020-12-31")],
}
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow # object dtype index
def test_parse_dates_dict_format_index(all_parsers):
# GH#51240
parser = all_parsers
data = """a,b
2019-12-31,31-12-2019
2020-12-31,31-12-2020"""
result = parser.read_csv(
StringIO(data), date_format={"a": "%Y-%m-%d"}, parse_dates=True, index_col=0
)
expected = DataFrame(
{
"b": ["31-12-2019", "31-12-2020"],
},
index=Index([Timestamp("2019-12-31"), Timestamp("2020-12-31")], name="a"),
)
tm.assert_frame_equal(result, expected)
def test_parse_dates_arrow_engine(all_parsers):
# GH#53295
parser = all_parsers
data = """a,b
2000-01-01 00:00:00,1
2000-01-01 00:00:01,1"""
result = parser.read_csv(StringIO(data), parse_dates=["a"])
# TODO: make unit check more specific
if parser.engine == "pyarrow":
result["a"] = result["a"].dt.as_unit("ns")
expected = DataFrame(
{
"a": [
Timestamp("2000-01-01 00:00:00"),
Timestamp("2000-01-01 00:00:01"),
],
"b": 1,
}
)
tm.assert_frame_equal(result, expected)
@xfail_pyarrow # object dtype index
def test_from_csv_with_mixed_offsets(all_parsers):
parser = all_parsers
data = "a\n2020-01-01T00:00:00+01:00\n2020-01-01T00:00:00+00:00"
result = parser.read_csv(StringIO(data), parse_dates=["a"])["a"]
expected = Series(
[
Timestamp("2020-01-01 00:00:00+01:00"),
Timestamp("2020-01-01 00:00:00+00:00"),
],
name="a",
index=[0, 1],
)
tm.assert_series_equal(result, expected)