Files
sirh/venv/lib/python3.12/site-packages/pandas/tests/io/test_compression.py
2026-04-29 11:52:03 +02:00

383 lines
12 KiB
Python

import gzip
import io
import os
import subprocess
import sys
import tarfile
import textwrap
import zipfile
import numpy as np
import pytest
from pandas.compat import is_platform_windows
import pandas as pd
import pandas._testing as tm
import pandas.io.common as icom
@pytest.mark.parametrize(
"obj",
[
pd.DataFrame(
100 * [[0.123456, 0.234567, 0.567567], [12.32112, 123123.2, 321321.2]],
columns=["X", "Y", "Z"],
),
pd.Series(100 * [0.123456, 0.234567, 0.567567], name="X"),
],
)
@pytest.mark.parametrize("method", ["to_pickle", "to_json", "to_csv"])
def test_compression_size(obj, method, compression_only, temp_file):
if compression_only == "tar":
compression_only = {"method": "tar", "mode": "w:gz"}
path = temp_file
getattr(obj, method)(path, compression=compression_only)
compressed_size = os.path.getsize(path)
getattr(obj, method)(path, compression=None)
uncompressed_size = os.path.getsize(path)
assert uncompressed_size > compressed_size
@pytest.mark.parametrize(
"obj",
[
pd.DataFrame(
100 * [[0.123456, 0.234567, 0.567567], [12.32112, 123123.2, 321321.2]],
columns=["X", "Y", "Z"],
),
pd.Series(100 * [0.123456, 0.234567, 0.567567], name="X"),
],
)
@pytest.mark.parametrize("method", ["to_csv", "to_json"])
def test_compression_size_fh(obj, method, compression_only, temp_file):
path = temp_file
with icom.get_handle(
path,
"w:gz" if compression_only == "tar" else "w",
compression=compression_only,
) as handles:
getattr(obj, method)(handles.handle)
assert not handles.handle.closed
compressed_size = os.path.getsize(path)
# Create a new temporary file for uncompressed comparison
path2 = temp_file.parent / f"{temp_file.stem}_uncompressed{temp_file.suffix}"
path2.touch()
with icom.get_handle(path2, "w", compression=None) as handles:
getattr(obj, method)(handles.handle)
assert not handles.handle.closed
uncompressed_size = os.path.getsize(path2)
assert uncompressed_size > compressed_size
@pytest.mark.parametrize(
"write_method, write_kwargs, read_method",
[
("to_csv", {"index": False}, pd.read_csv),
("to_json", {}, pd.read_json),
("to_pickle", {}, pd.read_pickle),
],
)
def test_dataframe_compression_defaults_to_infer(
write_method,
write_kwargs,
read_method,
compression_only,
compression_to_extension,
temp_file,
):
# GH22004
input = pd.DataFrame([[1.0, 0, -4], [3.4, 5, 2]], columns=["X", "Y", "Z"])
extension = compression_to_extension[compression_only]
path = temp_file.parent / f"compressed{extension}"
getattr(input, write_method)(path, **write_kwargs)
output = read_method(path, compression=compression_only)
tm.assert_frame_equal(output, input)
@pytest.mark.parametrize(
"write_method,write_kwargs,read_method,read_kwargs",
[
("to_csv", {"index": False, "header": True}, pd.read_csv, {"squeeze": True}),
("to_json", {}, pd.read_json, {"typ": "series"}),
("to_pickle", {}, pd.read_pickle, {}),
],
)
def test_series_compression_defaults_to_infer(
write_method,
write_kwargs,
read_method,
read_kwargs,
compression_only,
compression_to_extension,
temp_file,
):
# GH22004
input = pd.Series([0, 5, -2, 10], name="X")
extension = compression_to_extension[compression_only]
path = temp_file.parent / f"compressed{extension}"
getattr(input, write_method)(path, **write_kwargs)
if "squeeze" in read_kwargs:
kwargs = read_kwargs.copy()
del kwargs["squeeze"]
output = read_method(path, compression=compression_only, **kwargs).squeeze(
"columns"
)
else:
output = read_method(path, compression=compression_only, **read_kwargs)
tm.assert_series_equal(output, input, check_names=False)
def test_compression_warning(compression_only, temp_file):
# Assert that passing a file object to to_csv while explicitly specifying a
# compression protocol triggers a RuntimeWarning, as per GH21227.
df = pd.DataFrame(
100 * [[0.123456, 0.234567, 0.567567], [12.32112, 123123.2, 321321.2]],
columns=["X", "Y", "Z"],
)
path = temp_file
with icom.get_handle(path, "w", compression=compression_only) as handles:
with tm.assert_produces_warning(RuntimeWarning, match="has no effect"):
df.to_csv(handles.handle, compression=compression_only)
def test_compression_binary(compression_only, temp_file):
"""
Binary file handles support compression.
GH22555
"""
df = pd.DataFrame(
1.1 * np.arange(120).reshape((30, 4)),
columns=pd.Index(list("ABCD")),
index=pd.Index([f"i-{i}" for i in range(30)]),
)
# with a file
path = temp_file
with open(path, mode="wb") as file:
df.to_csv(file, mode="wb", compression=compression_only)
file.seek(0) # file shouldn't be closed
tm.assert_frame_equal(
df, pd.read_csv(path, index_col=0, compression=compression_only)
)
# with BytesIO
file = io.BytesIO()
df.to_csv(file, mode="wb", compression=compression_only)
file.seek(0) # file shouldn't be closed
tm.assert_frame_equal(
df, pd.read_csv(file, index_col=0, compression=compression_only)
)
def test_gzip_reproducibility_file_name(temp_file):
"""
Gzip should create reproducible archives with mtime.
Note: Archives created with different filenames will still be different!
GH 28103
"""
df = pd.DataFrame(
1.1 * np.arange(120).reshape((30, 4)),
columns=pd.Index(list("ABCD")),
index=pd.Index([f"i-{i}" for i in range(30)]),
)
compression_options = {"method": "gzip", "mtime": 1}
# test for filename
path = temp_file
df.to_csv(path, compression=compression_options)
output = path.read_bytes()
df.to_csv(path, compression=compression_options)
assert output == path.read_bytes()
def test_gzip_reproducibility_file_object():
"""
Gzip should create reproducible archives with mtime.
GH 28103
"""
df = pd.DataFrame(
1.1 * np.arange(120).reshape((30, 4)),
columns=pd.Index(list("ABCD")),
index=pd.Index([f"i-{i}" for i in range(30)]),
)
compression_options = {"method": "gzip", "mtime": 1}
# test for file object
buffer = io.BytesIO()
df.to_csv(buffer, compression=compression_options, mode="wb")
output = buffer.getvalue()
buffer = io.BytesIO()
df.to_csv(buffer, compression=compression_options, mode="wb")
assert output == buffer.getvalue()
@pytest.mark.single_cpu
def test_with_missing_lzma():
"""Tests if import pandas works when lzma is not present."""
# https://github.com/pandas-dev/pandas/issues/27575
code = textwrap.dedent(
"""\
import sys
sys.modules['lzma'] = None
import pandas
"""
)
subprocess.check_output([sys.executable, "-c", code], stderr=subprocess.PIPE)
@pytest.mark.single_cpu
def test_with_missing_lzma_runtime():
"""Tests if ModuleNotFoundError is hit when calling lzma without
having the module available.
"""
code = textwrap.dedent(
"""
import sys
import pytest
sys.modules['lzma'] = None
import pandas as pd
df = pd.DataFrame()
with pytest.raises(ModuleNotFoundError, match='import of lzma'):
df.to_csv('foo.csv', compression='xz')
"""
)
subprocess.check_output([sys.executable, "-c", code], stderr=subprocess.PIPE)
@pytest.mark.parametrize(
"obj",
[
pd.DataFrame(
100 * [[0.123456, 0.234567, 0.567567], [12.32112, 123123.2, 321321.2]],
columns=["X", "Y", "Z"],
),
pd.Series(100 * [0.123456, 0.234567, 0.567567], name="X"),
],
)
@pytest.mark.parametrize("method", ["to_pickle", "to_json", "to_csv"])
def test_gzip_compression_level(obj, method, temp_file):
# GH33196
path = temp_file
getattr(obj, method)(path, compression="gzip")
compressed_size_default = os.path.getsize(path)
getattr(obj, method)(path, compression={"method": "gzip", "compresslevel": 1})
compressed_size_fast = os.path.getsize(path)
assert compressed_size_default < compressed_size_fast
@pytest.mark.parametrize(
"obj",
[
pd.DataFrame(
100 * [[0.123456, 0.234567, 0.567567], [12.32112, 123123.2, 321321.2]],
columns=["X", "Y", "Z"],
),
pd.Series(100 * [0.123456, 0.234567, 0.567567], name="X"),
],
)
@pytest.mark.parametrize("method", ["to_pickle", "to_json", "to_csv"])
def test_xz_compression_level_read(obj, method, temp_file):
path = temp_file
getattr(obj, method)(path, compression="xz")
compressed_size_default = os.path.getsize(path)
getattr(obj, method)(path, compression={"method": "xz", "preset": 1})
compressed_size_fast = os.path.getsize(path)
assert compressed_size_default < compressed_size_fast
if method == "to_csv":
pd.read_csv(path, compression="xz")
@pytest.mark.parametrize(
"obj",
[
pd.DataFrame(
100 * [[0.123456, 0.234567, 0.567567], [12.32112, 123123.2, 321321.2]],
columns=["X", "Y", "Z"],
),
pd.Series(100 * [0.123456, 0.234567, 0.567567], name="X"),
],
)
@pytest.mark.parametrize("method", ["to_pickle", "to_json", "to_csv"])
def test_bzip_compression_level(obj, method, temp_file):
"""GH33196 bzip needs file size > 100k to show a size difference between
compression levels, so here we just check if the call works when
compression is passed as a dict.
"""
path = temp_file
getattr(obj, method)(path, compression={"method": "bz2", "compresslevel": 1})
@pytest.mark.parametrize(
"suffix,archive",
[
(".zip", zipfile.ZipFile),
(".tar", tarfile.TarFile),
],
)
def test_empty_archive_zip(suffix, archive, temp_file):
path = temp_file.parent / f"archive{suffix}"
with archive(path, "w"):
pass
with pytest.raises(ValueError, match="Zero files found"):
pd.read_csv(path)
def test_ambiguous_archive_zip(temp_file):
path = temp_file.parent / "archive.zip"
with zipfile.ZipFile(path, "w") as file:
file.writestr("a.csv", "foo,bar")
file.writestr("b.csv", "foo,bar")
with pytest.raises(ValueError, match="Multiple files found in ZIP file"):
pd.read_csv(path)
def test_ambiguous_archive_tar(tmp_path):
csvAPath = tmp_path / "a.csv"
with open(csvAPath, "w", encoding="utf-8") as a:
a.write("foo,bar\n")
csvBPath = tmp_path / "b.csv"
with open(csvBPath, "w", encoding="utf-8") as b:
b.write("foo,bar\n")
tarpath = tmp_path / "archive.tar"
with tarfile.TarFile(tarpath, "w") as tar:
tar.add(csvAPath, "a.csv")
tar.add(csvBPath, "b.csv")
with pytest.raises(ValueError, match="Multiple files found in TAR archive"):
pd.read_csv(tarpath)
def test_tar_gz_to_different_filename(temp_file):
file = temp_file.parent / "archive.foo"
pd.DataFrame(
[["1", "2"]],
columns=["foo", "bar"],
).to_csv(file, compression={"method": "tar", "mode": "w:gz"}, index=False)
with gzip.open(file) as uncompressed:
with tarfile.TarFile(fileobj=uncompressed) as archive:
members = archive.getmembers()
assert len(members) == 1
content = archive.extractfile(members[0]).read().decode("utf8")
if is_platform_windows():
expected = "foo,bar\r\n1,2\r\n"
else:
expected = "foo,bar\n1,2\n"
assert content == expected
def test_tar_no_error_on_close():
with io.BytesIO() as buffer:
with icom._BytesTarFile(fileobj=buffer, mode="w"):
pass