projektAI/venv/Lib/site-packages/pandas/tests/io/parser/test_na_values.py
2021-06-06 22:13:05 +02:00

569 lines
15 KiB
Python

"""
Tests that NA values are properly handled during
parsing for all of the parsers defined in parsers.py
"""
from io import StringIO
import numpy as np
import pytest
from pandas._libs.parsers import STR_NA_VALUES
from pandas import DataFrame, Index, MultiIndex
import pandas._testing as tm
def test_string_nas(all_parsers):
parser = all_parsers
data = """A,B,C
a,b,c
d,,f
,g,h
"""
result = parser.read_csv(StringIO(data))
expected = DataFrame(
[["a", "b", "c"], ["d", np.nan, "f"], [np.nan, "g", "h"]],
columns=["A", "B", "C"],
)
tm.assert_frame_equal(result, expected)
def test_detect_string_na(all_parsers):
parser = all_parsers
data = """A,B
foo,bar
NA,baz
NaN,nan
"""
expected = DataFrame(
[["foo", "bar"], [np.nan, "baz"], [np.nan, np.nan]], columns=["A", "B"]
)
result = parser.read_csv(StringIO(data))
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"na_values",
[
["-999.0", "-999"],
[-999, -999.0],
[-999.0, -999],
["-999.0"],
["-999"],
[-999.0],
[-999],
],
)
@pytest.mark.parametrize(
"data",
[
"""A,B
-999,1.2
2,-999
3,4.5
""",
"""A,B
-999,1.200
2,-999.000
3,4.500
""",
],
)
def test_non_string_na_values(all_parsers, data, na_values):
# see gh-3611: with an odd float format, we can't match
# the string "999.0" exactly but still need float matching
parser = all_parsers
expected = DataFrame([[np.nan, 1.2], [2.0, np.nan], [3.0, 4.5]], columns=["A", "B"])
result = parser.read_csv(StringIO(data), na_values=na_values)
tm.assert_frame_equal(result, expected)
def test_default_na_values(all_parsers):
_NA_VALUES = {
"-1.#IND",
"1.#QNAN",
"1.#IND",
"-1.#QNAN",
"#N/A",
"N/A",
"n/a",
"NA",
"<NA>",
"#NA",
"NULL",
"null",
"NaN",
"nan",
"-NaN",
"-nan",
"#N/A N/A",
"",
}
assert _NA_VALUES == STR_NA_VALUES
parser = all_parsers
nv = len(_NA_VALUES)
def f(i, v):
if i == 0:
buf = ""
elif i > 0:
buf = "".join([","] * i)
buf = f"{buf}{v}"
if i < nv - 1:
joined = "".join([","] * (nv - i - 1))
buf = f"{buf}{joined}"
return buf
data = StringIO("\n".join(f(i, v) for i, v in enumerate(_NA_VALUES)))
expected = DataFrame(np.nan, columns=range(nv), index=range(nv))
result = parser.read_csv(data, header=None)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize("na_values", ["baz", ["baz"]])
def test_custom_na_values(all_parsers, na_values):
parser = all_parsers
data = """A,B,C
ignore,this,row
1,NA,3
-1.#IND,5,baz
7,8,NaN
"""
expected = DataFrame(
[[1.0, np.nan, 3], [np.nan, 5, np.nan], [7, 8, np.nan]], columns=["A", "B", "C"]
)
result = parser.read_csv(StringIO(data), na_values=na_values, skiprows=[1])
tm.assert_frame_equal(result, expected)
def test_bool_na_values(all_parsers):
data = """A,B,C
True,False,True
NA,True,False
False,NA,True"""
parser = all_parsers
result = parser.read_csv(StringIO(data))
expected = DataFrame(
{
"A": np.array([True, np.nan, False], dtype=object),
"B": np.array([False, True, np.nan], dtype=object),
"C": [True, False, True],
}
)
tm.assert_frame_equal(result, expected)
def test_na_value_dict(all_parsers):
data = """A,B,C
foo,bar,NA
bar,foo,foo
foo,bar,NA
bar,foo,foo"""
parser = all_parsers
df = parser.read_csv(StringIO(data), na_values={"A": ["foo"], "B": ["bar"]})
expected = DataFrame(
{
"A": [np.nan, "bar", np.nan, "bar"],
"B": [np.nan, "foo", np.nan, "foo"],
"C": [np.nan, "foo", np.nan, "foo"],
}
)
tm.assert_frame_equal(df, expected)
@pytest.mark.parametrize(
"index_col,expected",
[
(
[0],
DataFrame({"b": [np.nan], "c": [1], "d": [5]}, index=Index([0], name="a")),
),
(
[0, 2],
DataFrame(
{"b": [np.nan], "d": [5]},
index=MultiIndex.from_tuples([(0, 1)], names=["a", "c"]),
),
),
(
["a", "c"],
DataFrame(
{"b": [np.nan], "d": [5]},
index=MultiIndex.from_tuples([(0, 1)], names=["a", "c"]),
),
),
],
)
def test_na_value_dict_multi_index(all_parsers, index_col, expected):
data = """\
a,b,c,d
0,NA,1,5
"""
parser = all_parsers
result = parser.read_csv(StringIO(data), na_values=set(), index_col=index_col)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"kwargs,expected",
[
(
dict(),
DataFrame(
{
"A": ["a", "b", np.nan, "d", "e", np.nan, "g"],
"B": [1, 2, 3, 4, 5, 6, 7],
"C": ["one", "two", "three", np.nan, "five", np.nan, "seven"],
}
),
),
(
dict(na_values={"A": [], "C": []}, keep_default_na=False),
DataFrame(
{
"A": ["a", "b", "", "d", "e", "nan", "g"],
"B": [1, 2, 3, 4, 5, 6, 7],
"C": ["one", "two", "three", "nan", "five", "", "seven"],
}
),
),
(
dict(na_values=["a"], keep_default_na=False),
DataFrame(
{
"A": [np.nan, "b", "", "d", "e", "nan", "g"],
"B": [1, 2, 3, 4, 5, 6, 7],
"C": ["one", "two", "three", "nan", "five", "", "seven"],
}
),
),
(
dict(na_values={"A": [], "C": []}),
DataFrame(
{
"A": ["a", "b", np.nan, "d", "e", np.nan, "g"],
"B": [1, 2, 3, 4, 5, 6, 7],
"C": ["one", "two", "three", np.nan, "five", np.nan, "seven"],
}
),
),
],
)
def test_na_values_keep_default(all_parsers, kwargs, expected):
data = """\
A,B,C
a,1,one
b,2,two
,3,three
d,4,nan
e,5,five
nan,6,
g,7,seven
"""
parser = all_parsers
result = parser.read_csv(StringIO(data), **kwargs)
tm.assert_frame_equal(result, expected)
def test_no_na_values_no_keep_default(all_parsers):
# see gh-4318: passing na_values=None and
# keep_default_na=False yields 'None" as a na_value
data = """\
A,B,C
a,1,None
b,2,two
,3,None
d,4,nan
e,5,five
nan,6,
g,7,seven
"""
parser = all_parsers
result = parser.read_csv(StringIO(data), keep_default_na=False)
expected = DataFrame(
{
"A": ["a", "b", "", "d", "e", "nan", "g"],
"B": [1, 2, 3, 4, 5, 6, 7],
"C": ["None", "two", "None", "nan", "five", "", "seven"],
}
)
tm.assert_frame_equal(result, expected)
def test_no_keep_default_na_dict_na_values(all_parsers):
# see gh-19227
data = "a,b\n,2"
parser = all_parsers
result = parser.read_csv(
StringIO(data), na_values={"b": ["2"]}, keep_default_na=False
)
expected = DataFrame({"a": [""], "b": [np.nan]})
tm.assert_frame_equal(result, expected)
def test_no_keep_default_na_dict_na_scalar_values(all_parsers):
# see gh-19227
#
# Scalar values shouldn't cause the parsing to crash or fail.
data = "a,b\n1,2"
parser = all_parsers
df = parser.read_csv(StringIO(data), na_values={"b": 2}, keep_default_na=False)
expected = DataFrame({"a": [1], "b": [np.nan]})
tm.assert_frame_equal(df, expected)
@pytest.mark.parametrize("col_zero_na_values", [113125, "113125"])
def test_no_keep_default_na_dict_na_values_diff_reprs(all_parsers, col_zero_na_values):
# see gh-19227
data = """\
113125,"blah","/blaha",kjsdkj,412.166,225.874,214.008
729639,"qwer","",asdfkj,466.681,,252.373
"""
parser = all_parsers
expected = DataFrame(
{
0: [np.nan, 729639.0],
1: [np.nan, "qwer"],
2: ["/blaha", np.nan],
3: ["kjsdkj", "asdfkj"],
4: [412.166, 466.681],
5: ["225.874", ""],
6: [np.nan, 252.373],
}
)
result = parser.read_csv(
StringIO(data),
header=None,
keep_default_na=False,
na_values={2: "", 6: "214.008", 1: "blah", 0: col_zero_na_values},
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"na_filter,row_data",
[
(True, [[1, "A"], [np.nan, np.nan], [3, "C"]]),
(False, [["1", "A"], ["nan", "B"], ["3", "C"]]),
],
)
def test_na_values_na_filter_override(all_parsers, na_filter, row_data):
data = """\
A,B
1,A
nan,B
3,C
"""
parser = all_parsers
result = parser.read_csv(StringIO(data), na_values=["B"], na_filter=na_filter)
expected = DataFrame(row_data, columns=["A", "B"])
tm.assert_frame_equal(result, expected)
def test_na_trailing_columns(all_parsers):
parser = all_parsers
data = """Date,Currency,Symbol,Type,Units,UnitPrice,Cost,Tax
2012-03-14,USD,AAPL,BUY,1000
2012-05-12,USD,SBUX,SELL,500"""
# Trailing columns should be all NaN.
result = parser.read_csv(StringIO(data))
expected = DataFrame(
[
["2012-03-14", "USD", "AAPL", "BUY", 1000, np.nan, np.nan, np.nan],
["2012-05-12", "USD", "SBUX", "SELL", 500, np.nan, np.nan, np.nan],
],
columns=[
"Date",
"Currency",
"Symbol",
"Type",
"Units",
"UnitPrice",
"Cost",
"Tax",
],
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"na_values,row_data",
[
(1, [[np.nan, 2.0], [2.0, np.nan]]),
({"a": 2, "b": 1}, [[1.0, 2.0], [np.nan, np.nan]]),
],
)
def test_na_values_scalar(all_parsers, na_values, row_data):
# see gh-12224
parser = all_parsers
names = ["a", "b"]
data = "1,2\n2,1"
result = parser.read_csv(StringIO(data), names=names, na_values=na_values)
expected = DataFrame(row_data, columns=names)
tm.assert_frame_equal(result, expected)
def test_na_values_dict_aliasing(all_parsers):
parser = all_parsers
na_values = {"a": 2, "b": 1}
na_values_copy = na_values.copy()
names = ["a", "b"]
data = "1,2\n2,1"
expected = DataFrame([[1.0, 2.0], [np.nan, np.nan]], columns=names)
result = parser.read_csv(StringIO(data), names=names, na_values=na_values)
tm.assert_frame_equal(result, expected)
tm.assert_dict_equal(na_values, na_values_copy)
def test_na_values_dict_col_index(all_parsers):
# see gh-14203
data = "a\nfoo\n1"
parser = all_parsers
na_values = {0: "foo"}
result = parser.read_csv(StringIO(data), na_values=na_values)
expected = DataFrame({"a": [np.nan, 1]})
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"data,kwargs,expected",
[
(
str(2 ** 63) + "\n" + str(2 ** 63 + 1),
dict(na_values=[2 ** 63]),
DataFrame([str(2 ** 63), str(2 ** 63 + 1)]),
),
(str(2 ** 63) + ",1" + "\n,2", dict(), DataFrame([[str(2 ** 63), 1], ["", 2]])),
(str(2 ** 63) + "\n1", dict(na_values=[2 ** 63]), DataFrame([np.nan, 1])),
],
)
def test_na_values_uint64(all_parsers, data, kwargs, expected):
# see gh-14983
parser = all_parsers
result = parser.read_csv(StringIO(data), header=None, **kwargs)
tm.assert_frame_equal(result, expected)
def test_empty_na_values_no_default_with_index(all_parsers):
# see gh-15835
data = "a,1\nb,2"
parser = all_parsers
expected = DataFrame({"1": [2]}, index=Index(["b"], name="a"))
result = parser.read_csv(StringIO(data), index_col=0, keep_default_na=False)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"na_filter,index_data", [(False, ["", "5"]), (True, [np.nan, 5.0])]
)
def test_no_na_filter_on_index(all_parsers, na_filter, index_data):
# see gh-5239
#
# Don't parse NA-values in index unless na_filter=True
parser = all_parsers
data = "a,b,c\n1,,3\n4,5,6"
expected = DataFrame({"a": [1, 4], "c": [3, 6]}, index=Index(index_data, name="b"))
result = parser.read_csv(StringIO(data), index_col=[1], na_filter=na_filter)
tm.assert_frame_equal(result, expected)
def test_inf_na_values_with_int_index(all_parsers):
# see gh-17128
parser = all_parsers
data = "idx,col1,col2\n1,3,4\n2,inf,-inf"
# Don't fail with OverflowError with inf's and integer index column.
out = parser.read_csv(StringIO(data), index_col=[0], na_values=["inf", "-inf"])
expected = DataFrame(
{"col1": [3, np.nan], "col2": [4, np.nan]}, index=Index([1, 2], name="idx")
)
tm.assert_frame_equal(out, expected)
@pytest.mark.parametrize("na_filter", [True, False])
def test_na_values_with_dtype_str_and_na_filter(all_parsers, na_filter):
# see gh-20377
parser = all_parsers
data = "a,b,c\n1,,3\n4,5,6"
# na_filter=True --> missing value becomes NaN.
# na_filter=False --> missing value remains empty string.
empty = np.nan if na_filter else ""
expected = DataFrame({"a": ["1", "4"], "b": [empty, "5"], "c": ["3", "6"]})
result = parser.read_csv(StringIO(data), na_filter=na_filter, dtype=str)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"data, na_values",
[
("false,1\n,1\ntrue", None),
("false,1\nnull,1\ntrue", None),
("false,1\nnan,1\ntrue", None),
("false,1\nfoo,1\ntrue", "foo"),
("false,1\nfoo,1\ntrue", ["foo"]),
("false,1\nfoo,1\ntrue", {"a": "foo"}),
],
)
def test_cast_NA_to_bool_raises_error(all_parsers, data, na_values):
parser = all_parsers
msg = (
"(Bool column has NA values in column [0a])|"
"(cannot safely convert passed user dtype of "
"bool for object dtyped data in column 0)"
)
with pytest.raises(ValueError, match=msg):
parser.read_csv(
StringIO(data),
header=None,
names=["a", "b"],
dtype={"a": "bool"},
na_values=na_values,
)
def test_str_nan_dropped(all_parsers):
# see gh-21131
parser = all_parsers
data = """File: small.csv,,
10010010233,0123,654
foo,,bar
01001000155,4530,898"""
result = parser.read_csv(
StringIO(data),
header=None,
names=["col1", "col2", "col3"],
dtype={"col1": str, "col2": str, "col3": str},
).dropna()
expected = DataFrame(
{
"col1": ["10010010233", "01001000155"],
"col2": ["0123", "4530"],
"col3": ["654", "898"],
},
index=[1, 3],
)
tm.assert_frame_equal(result, expected)