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

476 lines
16 KiB
Python

"""
Tests for the pandas.io.common functionalities
"""
import codecs
from io import BytesIO, StringIO
import mmap
import os
from pathlib import Path
import pytest
from pandas.compat import is_platform_windows
import pandas.util._test_decorators as td
import pandas as pd
import pandas._testing as tm
import pandas.io.common as icom
class CustomFSPath:
"""For testing fspath on unknown objects"""
def __init__(self, path):
self.path = path
def __fspath__(self):
return self.path
# Functions that consume a string path and return a string or path-like object
path_types = [str, CustomFSPath, Path]
try:
from py.path import local as LocalPath
path_types.append(LocalPath)
except ImportError:
pass
HERE = os.path.abspath(os.path.dirname(__file__))
# https://github.com/cython/cython/issues/1720
@pytest.mark.filterwarnings("ignore:can't resolve package:ImportWarning")
class TestCommonIOCapabilities:
data1 = """index,A,B,C,D
foo,2,3,4,5
bar,7,8,9,10
baz,12,13,14,15
qux,12,13,14,15
foo2,12,13,14,15
bar2,12,13,14,15
"""
def test_expand_user(self):
filename = "~/sometest"
expanded_name = icom._expand_user(filename)
assert expanded_name != filename
assert os.path.isabs(expanded_name)
assert os.path.expanduser(filename) == expanded_name
def test_expand_user_normal_path(self):
filename = "/somefolder/sometest"
expanded_name = icom._expand_user(filename)
assert expanded_name == filename
assert os.path.expanduser(filename) == expanded_name
def test_stringify_path_pathlib(self):
rel_path = icom.stringify_path(Path("."))
assert rel_path == "."
redundant_path = icom.stringify_path(Path("foo//bar"))
assert redundant_path == os.path.join("foo", "bar")
@td.skip_if_no("py.path")
def test_stringify_path_localpath(self):
path = os.path.join("foo", "bar")
abs_path = os.path.abspath(path)
lpath = LocalPath(path)
assert icom.stringify_path(lpath) == abs_path
def test_stringify_path_fspath(self):
p = CustomFSPath("foo/bar.csv")
result = icom.stringify_path(p)
assert result == "foo/bar.csv"
def test_stringify_file_and_path_like(self):
# GH 38125: do not stringify file objects that are also path-like
fsspec = pytest.importorskip("fsspec")
with tm.ensure_clean() as path:
with fsspec.open(f"file://{path}", mode="wb") as fsspec_obj:
assert fsspec_obj == icom.stringify_path(fsspec_obj)
@pytest.mark.parametrize(
"extension,expected",
[
("", None),
(".gz", "gzip"),
(".bz2", "bz2"),
(".zip", "zip"),
(".xz", "xz"),
(".GZ", "gzip"),
(".BZ2", "bz2"),
(".ZIP", "zip"),
(".XZ", "xz"),
],
)
@pytest.mark.parametrize("path_type", path_types)
def test_infer_compression_from_path(self, extension, expected, path_type):
path = path_type("foo/bar.csv" + extension)
compression = icom.infer_compression(path, compression="infer")
assert compression == expected
@pytest.mark.parametrize("path_type", [str, CustomFSPath, Path])
def test_get_handle_with_path(self, path_type):
# ignore LocalPath: it creates strange paths: /absolute/~/sometest
filename = path_type("~/sometest")
with icom.get_handle(filename, "w") as handles:
assert os.path.isabs(handles.handle.name)
assert os.path.expanduser(filename) == handles.handle.name
def test_get_handle_with_buffer(self):
input_buffer = StringIO()
with icom.get_handle(input_buffer, "r") as handles:
assert handles.handle == input_buffer
assert not input_buffer.closed
input_buffer.close()
def test_iterator(self):
with pd.read_csv(StringIO(self.data1), chunksize=1) as reader:
result = pd.concat(reader, ignore_index=True)
expected = pd.read_csv(StringIO(self.data1))
tm.assert_frame_equal(result, expected)
# GH12153
with pd.read_csv(StringIO(self.data1), chunksize=1) as it:
first = next(it)
tm.assert_frame_equal(first, expected.iloc[[0]])
tm.assert_frame_equal(pd.concat(it), expected.iloc[1:])
@pytest.mark.parametrize(
"reader, module, error_class, fn_ext",
[
(pd.read_csv, "os", FileNotFoundError, "csv"),
(pd.read_fwf, "os", FileNotFoundError, "txt"),
(pd.read_excel, "xlrd", FileNotFoundError, "xlsx"),
(pd.read_feather, "pyarrow", IOError, "feather"),
(pd.read_hdf, "tables", FileNotFoundError, "h5"),
(pd.read_stata, "os", FileNotFoundError, "dta"),
(pd.read_sas, "os", FileNotFoundError, "sas7bdat"),
(pd.read_json, "os", ValueError, "json"),
(pd.read_pickle, "os", FileNotFoundError, "pickle"),
],
)
def test_read_non_existent(self, reader, module, error_class, fn_ext):
pytest.importorskip(module)
path = os.path.join(HERE, "data", "does_not_exist." + fn_ext)
msg1 = fr"File (b')?.+does_not_exist\.{fn_ext}'? does not exist"
msg2 = fr"\[Errno 2\] No such file or directory: '.+does_not_exist\.{fn_ext}'"
msg3 = "Expected object or value"
msg4 = "path_or_buf needs to be a string file path or file-like"
msg5 = (
fr"\[Errno 2\] File .+does_not_exist\.{fn_ext} does not exist: "
fr"'.+does_not_exist\.{fn_ext}'"
)
msg6 = fr"\[Errno 2\] 没有那个文件或目录: '.+does_not_exist\.{fn_ext}'"
msg7 = (
fr"\[Errno 2\] File o directory non esistente: '.+does_not_exist\.{fn_ext}'"
)
msg8 = fr"Failed to open local file.+does_not_exist\.{fn_ext}"
with pytest.raises(
error_class,
match=fr"({msg1}|{msg2}|{msg3}|{msg4}|{msg5}|{msg6}|{msg7}|{msg8})",
):
reader(path)
@pytest.mark.parametrize(
"reader, module, error_class, fn_ext",
[
(pd.read_csv, "os", FileNotFoundError, "csv"),
(pd.read_table, "os", FileNotFoundError, "csv"),
(pd.read_fwf, "os", FileNotFoundError, "txt"),
(pd.read_excel, "xlrd", FileNotFoundError, "xlsx"),
(pd.read_feather, "pyarrow", IOError, "feather"),
(pd.read_hdf, "tables", FileNotFoundError, "h5"),
(pd.read_stata, "os", FileNotFoundError, "dta"),
(pd.read_sas, "os", FileNotFoundError, "sas7bdat"),
(pd.read_json, "os", ValueError, "json"),
(pd.read_pickle, "os", FileNotFoundError, "pickle"),
],
)
def test_read_expands_user_home_dir(
self, reader, module, error_class, fn_ext, monkeypatch
):
pytest.importorskip(module)
path = os.path.join("~", "does_not_exist." + fn_ext)
monkeypatch.setattr(icom, "_expand_user", lambda x: os.path.join("foo", x))
msg1 = fr"File (b')?.+does_not_exist\.{fn_ext}'? does not exist"
msg2 = fr"\[Errno 2\] No such file or directory: '.+does_not_exist\.{fn_ext}'"
msg3 = "Unexpected character found when decoding 'false'"
msg4 = "path_or_buf needs to be a string file path or file-like"
msg5 = (
fr"\[Errno 2\] File .+does_not_exist\.{fn_ext} does not exist: "
fr"'.+does_not_exist\.{fn_ext}'"
)
msg6 = fr"\[Errno 2\] 没有那个文件或目录: '.+does_not_exist\.{fn_ext}'"
msg7 = (
fr"\[Errno 2\] File o directory non esistente: '.+does_not_exist\.{fn_ext}'"
)
msg8 = fr"Failed to open local file.+does_not_exist\.{fn_ext}"
with pytest.raises(
error_class,
match=fr"({msg1}|{msg2}|{msg3}|{msg4}|{msg5}|{msg6}|{msg7}|{msg8})",
):
reader(path)
@pytest.mark.parametrize(
"reader, module, path",
[
(pd.read_csv, "os", ("io", "data", "csv", "iris.csv")),
(pd.read_table, "os", ("io", "data", "csv", "iris.csv")),
(
pd.read_fwf,
"os",
("io", "data", "fixed_width", "fixed_width_format.txt"),
),
(pd.read_excel, "xlrd", ("io", "data", "excel", "test1.xlsx")),
(
pd.read_feather,
"pyarrow",
("io", "data", "feather", "feather-0_3_1.feather"),
),
(
pd.read_hdf,
"tables",
("io", "data", "legacy_hdf", "datetimetz_object.h5"),
),
(pd.read_stata, "os", ("io", "data", "stata", "stata10_115.dta")),
(pd.read_sas, "os", ("io", "sas", "data", "test1.sas7bdat")),
(pd.read_json, "os", ("io", "json", "data", "tsframe_v012.json")),
(
pd.read_pickle,
"os",
("io", "data", "pickle", "categorical.0.25.0.pickle"),
),
],
)
def test_read_fspath_all(self, reader, module, path, datapath):
pytest.importorskip(module)
path = datapath(*path)
mypath = CustomFSPath(path)
result = reader(mypath)
expected = reader(path)
if path.endswith(".pickle"):
# categorical
tm.assert_categorical_equal(result, expected)
else:
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"writer_name, writer_kwargs, module",
[
("to_csv", {}, "os"),
("to_excel", {"engine": "xlwt"}, "xlwt"),
("to_feather", {}, "pyarrow"),
("to_html", {}, "os"),
("to_json", {}, "os"),
("to_latex", {}, "os"),
("to_pickle", {}, "os"),
("to_stata", {"time_stamp": pd.to_datetime("2019-01-01 00:00")}, "os"),
],
)
def test_write_fspath_all(self, writer_name, writer_kwargs, module):
p1 = tm.ensure_clean("string")
p2 = tm.ensure_clean("fspath")
df = pd.DataFrame({"A": [1, 2]})
with p1 as string, p2 as fspath:
pytest.importorskip(module)
mypath = CustomFSPath(fspath)
writer = getattr(df, writer_name)
writer(string, **writer_kwargs)
with open(string, "rb") as f:
expected = f.read()
writer(mypath, **writer_kwargs)
with open(fspath, "rb") as f:
result = f.read()
assert result == expected
def test_write_fspath_hdf5(self):
# Same test as write_fspath_all, except HDF5 files aren't
# necessarily byte-for-byte identical for a given dataframe, so we'll
# have to read and compare equality
pytest.importorskip("tables")
df = pd.DataFrame({"A": [1, 2]})
p1 = tm.ensure_clean("string")
p2 = tm.ensure_clean("fspath")
with p1 as string, p2 as fspath:
mypath = CustomFSPath(fspath)
df.to_hdf(mypath, key="bar")
df.to_hdf(string, key="bar")
result = pd.read_hdf(fspath, key="bar")
expected = pd.read_hdf(string, key="bar")
tm.assert_frame_equal(result, expected)
@pytest.fixture
def mmap_file(datapath):
return datapath("io", "data", "csv", "test_mmap.csv")
class TestMMapWrapper:
def test_constructor_bad_file(self, mmap_file):
non_file = StringIO("I am not a file")
non_file.fileno = lambda: -1
# the error raised is different on Windows
if is_platform_windows():
msg = "The parameter is incorrect"
err = OSError
else:
msg = "[Errno 22]"
err = mmap.error
with pytest.raises(err, match=msg):
icom._MMapWrapper(non_file)
target = open(mmap_file)
target.close()
msg = "I/O operation on closed file"
with pytest.raises(ValueError, match=msg):
icom._MMapWrapper(target)
def test_get_attr(self, mmap_file):
with open(mmap_file) as target:
wrapper = icom._MMapWrapper(target)
attrs = dir(wrapper.mmap)
attrs = [attr for attr in attrs if not attr.startswith("__")]
attrs.append("__next__")
for attr in attrs:
assert hasattr(wrapper, attr)
assert not hasattr(wrapper, "foo")
def test_next(self, mmap_file):
with open(mmap_file) as target:
wrapper = icom._MMapWrapper(target)
lines = target.readlines()
for line in lines:
next_line = next(wrapper)
assert next_line.strip() == line.strip()
with pytest.raises(StopIteration, match=r"^$"):
next(wrapper)
def test_unknown_engine(self):
with tm.ensure_clean() as path:
df = tm.makeDataFrame()
df.to_csv(path)
with pytest.raises(ValueError, match="Unknown engine"):
pd.read_csv(path, engine="pyt")
def test_binary_mode(self):
"""
'encoding' shouldn't be passed to 'open' in binary mode.
GH 35058
"""
with tm.ensure_clean() as path:
df = tm.makeDataFrame()
df.to_csv(path, mode="w+b")
tm.assert_frame_equal(df, pd.read_csv(path, index_col=0))
@pytest.mark.parametrize("encoding", ["utf-16", "utf-32"])
@pytest.mark.parametrize("compression_", ["bz2", "xz"])
def test_warning_missing_utf_bom(self, encoding, compression_):
"""
bz2 and xz do not write the byte order mark (BOM) for utf-16/32.
https://stackoverflow.com/questions/55171439
GH 35681
"""
df = tm.makeDataFrame()
with tm.ensure_clean() as path:
with tm.assert_produces_warning(UnicodeWarning):
df.to_csv(path, compression=compression_, encoding=encoding)
# reading should fail (otherwise we wouldn't need the warning)
with pytest.raises(Exception):
pd.read_csv(path, compression=compression_, encoding=encoding)
def test_is_fsspec_url():
assert icom.is_fsspec_url("gcs://pandas/somethingelse.com")
assert icom.is_fsspec_url("gs://pandas/somethingelse.com")
# the following is the only remote URL that is handled without fsspec
assert not icom.is_fsspec_url("http://pandas/somethingelse.com")
assert not icom.is_fsspec_url("random:pandas/somethingelse.com")
assert not icom.is_fsspec_url("/local/path")
assert not icom.is_fsspec_url("relative/local/path")
def test_default_errors():
# GH 38989
with tm.ensure_clean() as path:
file = Path(path)
file.write_bytes(b"\xe4\na\n1")
tm.assert_frame_equal(pd.read_csv(file, skiprows=[0]), pd.DataFrame({"a": [1]}))
@pytest.mark.parametrize("encoding", [None, "utf-8"])
@pytest.mark.parametrize("format", ["csv", "json"])
def test_codecs_encoding(encoding, format):
# GH39247
expected = tm.makeDataFrame()
with tm.ensure_clean() as path:
with codecs.open(path, mode="w", encoding=encoding) as handle:
getattr(expected, f"to_{format}")(handle)
with codecs.open(path, mode="r", encoding=encoding) as handle:
if format == "csv":
df = pd.read_csv(handle, index_col=0)
else:
df = pd.read_json(handle)
tm.assert_frame_equal(expected, df)
def test_codecs_get_writer_reader():
# GH39247
expected = tm.makeDataFrame()
with tm.ensure_clean() as path:
with open(path, "wb") as handle:
with codecs.getwriter("utf-8")(handle) as encoded:
expected.to_csv(encoded)
with open(path, "rb") as handle:
with codecs.getreader("utf-8")(handle) as encoded:
df = pd.read_csv(encoded, index_col=0)
tm.assert_frame_equal(expected, df)
@pytest.mark.parametrize(
"io_class,mode,msg",
[
(BytesIO, "t", "a bytes-like object is required, not 'str'"),
(StringIO, "b", "string argument expected, got 'bytes'"),
],
)
def test_explicit_encoding(io_class, mode, msg):
# GH39247; this test makes sure that if a user provides mode="*t" or "*b",
# it is used. In the case of this test it leads to an error as intentionally the
# wrong mode is requested
expected = tm.makeDataFrame()
with io_class() as buffer:
with pytest.raises(TypeError, match=msg):
expected.to_csv(buffer, mode=f"w{mode}")