Alle Dateien aus dem Pythonkurs
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

213 lines
7.3 KiB

"""
Tests that features that are currently unsupported in
either the Python or C parser are actually enforced
and are clearly communicated to the user.
Ultimately, the goal is to remove test cases from this
test suite as new feature support is added to the parsers.
"""
from io import StringIO
import os
from pathlib import Path
import pytest
from pandas.compat import (
is_ci_environment,
is_platform_mac,
is_platform_windows,
)
from pandas.errors import ParserError
import pandas._testing as tm
from pandas.io.parsers import read_csv
import pandas.io.parsers.readers as parsers
@pytest.fixture(params=["python", "python-fwf"], ids=lambda val: val)
def python_engine(request):
return request.param
class TestUnsupportedFeatures:
def test_mangle_dupe_cols_false(self):
# see gh-12935
data = "a b c\n1 2 3"
for engine in ("c", "python"):
with pytest.raises(TypeError, match="unexpected keyword"):
read_csv(StringIO(data), engine=engine, mangle_dupe_cols=True)
def test_c_engine(self):
# see gh-6607
data = "a b c\n1 2 3"
msg = "does not support"
# specify C engine with unsupported options (raise)
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), engine="c", sep=None, delim_whitespace=False)
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), engine="c", sep=r"\s")
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), engine="c", sep="\t", quotechar=chr(128))
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), engine="c", skipfooter=1)
# specify C-unsupported options without python-unsupported options
with tm.assert_produces_warning(parsers.ParserWarning):
read_csv(StringIO(data), sep=None, delim_whitespace=False)
with tm.assert_produces_warning(parsers.ParserWarning):
read_csv(StringIO(data), sep=r"\s")
with tm.assert_produces_warning(parsers.ParserWarning):
read_csv(StringIO(data), sep="\t", quotechar=chr(128))
with tm.assert_produces_warning(parsers.ParserWarning):
read_csv(StringIO(data), skipfooter=1)
text = """ A B C D E
one two three four
a b 10.0032 5 -0.5109 -2.3358 -0.4645 0.05076 0.3640
a q 20 4 0.4473 1.4152 0.2834 1.00661 0.1744
x q 30 3 -0.6662 -0.5243 -0.3580 0.89145 2.5838"""
msg = "Error tokenizing data"
with pytest.raises(ParserError, match=msg):
read_csv(StringIO(text), sep="\\s+")
with pytest.raises(ParserError, match=msg):
read_csv(StringIO(text), engine="c", sep="\\s+")
msg = "Only length-1 thousands markers supported"
data = """A|B|C
1|2,334|5
10|13|10.
"""
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), thousands=",,")
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), thousands="")
msg = "Only length-1 line terminators supported"
data = "a,b,c~~1,2,3~~4,5,6"
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), lineterminator="~~")
def test_python_engine(self, python_engine):
from pandas.io.parsers.readers import _python_unsupported as py_unsupported
data = """1,2,3,,
1,2,3,4,
1,2,3,4,5
1,2,,,
1,2,3,4,"""
for default in py_unsupported:
msg = (
f"The {repr(default)} option is not "
f"supported with the {repr(python_engine)} engine"
)
kwargs = {default: object()}
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), engine=python_engine, **kwargs)
def test_python_engine_file_no_iter(self, python_engine):
# see gh-16530
class NoNextBuffer:
def __init__(self, csv_data) -> None:
self.data = csv_data
def __next__(self):
return self.data.__next__()
def read(self):
return self.data
def readline(self):
return self.data
data = "a\n1"
msg = "'NoNextBuffer' object is not iterable|argument 1 must be an iterator"
with pytest.raises(TypeError, match=msg):
read_csv(NoNextBuffer(data), engine=python_engine)
def test_pyarrow_engine(self):
from pandas.io.parsers.readers import _pyarrow_unsupported as pa_unsupported
data = """1,2,3,,
1,2,3,4,
1,2,3,4,5
1,2,,,
1,2,3,4,"""
for default in pa_unsupported:
msg = (
f"The {repr(default)} option is not "
f"supported with the 'pyarrow' engine"
)
kwargs = {default: object()}
default_needs_bool = {"warn_bad_lines", "error_bad_lines"}
if default == "dialect":
kwargs[default] = "excel" # test a random dialect
elif default in default_needs_bool:
kwargs[default] = True
elif default == "on_bad_lines":
kwargs[default] = "warn"
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), engine="pyarrow", **kwargs)
def test_on_bad_lines_callable_python_only(self, all_parsers):
# GH 5686
sio = StringIO("a,b\n1,2")
bad_lines_func = lambda x: x
parser = all_parsers
if all_parsers.engine != "python":
msg = "on_bad_line can only be a callable function if engine='python'"
with pytest.raises(ValueError, match=msg):
parser.read_csv(sio, on_bad_lines=bad_lines_func)
else:
parser.read_csv(sio, on_bad_lines=bad_lines_func)
def test_close_file_handle_on_invalid_usecols(all_parsers):
# GH 45384
parser = all_parsers
error = ValueError
if parser.engine == "pyarrow":
pyarrow = pytest.importorskip("pyarrow")
error = pyarrow.lib.ArrowKeyError
if is_ci_environment() and (is_platform_windows() or is_platform_mac()):
# GH#45547 causes timeouts on windows/mac builds
pytest.skip("GH#45547 causing timeouts on windows/mac builds 2022-01-22")
with tm.ensure_clean("test.csv") as fname:
Path(fname).write_text("col1,col2\na,b\n1,2", encoding="utf-8")
with tm.assert_produces_warning(False):
with pytest.raises(error, match="col3"):
parser.read_csv(fname, usecols=["col1", "col2", "col3"])
# unlink fails on windows if file handles still point to it
os.unlink(fname)
def test_invalid_file_inputs(request, all_parsers):
# GH#45957
parser = all_parsers
if parser.engine == "python":
request.node.add_marker(
pytest.mark.xfail(reason=f"{parser.engine} engine supports lists.")
)
with pytest.raises(ValueError, match="Invalid"):
parser.read_csv([])
def test_invalid_dtype_backend(all_parsers):
parser = all_parsers
msg = (
"dtype_backend numpy is invalid, only 'numpy_nullable' and "
"'pyarrow' are allowed."
)
with pytest.raises(ValueError, match=msg):
parser.read_csv("test", dtype_backend="numpy")