projektAI/venv/Lib/site-packages/pandas/tests/io/parser/test_unsupported.py

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2021-06-06 22:13:05 +02:00
"""
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 pytest
from pandas.errors import ParserError
import pandas._testing as tm
import pandas.io.parsers as parsers
from pandas.io.parsers import read_csv
@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"
msg = "is not supported"
for engine in ("c", "python"):
with pytest.raises(ValueError, match=msg):
read_csv(StringIO(data), engine=engine, mangle_dupe_cols=False)
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 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_next(self, python_engine):
# see gh-16530
class NoNextBuffer:
def __init__(self, csv_data):
self.data = csv_data
def __iter__(self):
return self
def read(self):
return self.data
data = "a\n1"
msg = "The 'python' engine cannot iterate"
with pytest.raises(ValueError, match=msg):
read_csv(NoNextBuffer(data), engine=python_engine)