manyi/venv/Lib/site-packages/pandas/tests/io/parser/test_quoting.py

# -*- coding: utf-8 -*-

"""
Tests that quoting specifications are properly handled
during parsing for all of the parsers defined in parsers.py
"""

import csv

import pytest

from pandas.compat import PY2, StringIO, u
from pandas.errors import ParserError

from pandas import DataFrame
import pandas.util.testing as tm


@pytest.mark.parametrize("kwargs,msg", [
    (dict(quotechar="foo"), '"quotechar" must be a(n)? 1-character string'),
    (dict(quotechar=None, quoting=csv.QUOTE_MINIMAL),
     "quotechar must be set if quoting enabled"),
    (dict(quotechar=2), '"quotechar" must be string, not int')
])
def test_bad_quote_char(all_parsers, kwargs, msg):
    data = "1,2,3"
    parser = all_parsers

    with pytest.raises(TypeError, match=msg):
        parser.read_csv(StringIO(data), **kwargs)


@pytest.mark.parametrize("quoting,msg", [
    ("foo", '"quoting" must be an integer'),
    (5, 'bad "quoting" value'),  # quoting must be in the range [0, 3]
])
def test_bad_quoting(all_parsers, quoting, msg):
    data = "1,2,3"
    parser = all_parsers

    with pytest.raises(TypeError, match=msg):
        parser.read_csv(StringIO(data), quoting=quoting)


def test_quote_char_basic(all_parsers):
    parser = all_parsers
    data = 'a,b,c\n1,2,"cat"'
    expected = DataFrame([[1, 2, "cat"]],
                         columns=["a", "b", "c"])

    result = parser.read_csv(StringIO(data), quotechar='"')
    tm.assert_frame_equal(result, expected)


@pytest.mark.parametrize("quote_char", ["~", "*", "%", "$", "@", "P"])
def test_quote_char_various(all_parsers, quote_char):
    parser = all_parsers
    expected = DataFrame([[1, 2, "cat"]],
                         columns=["a", "b", "c"])

    data = 'a,b,c\n1,2,"cat"'
    new_data = data.replace('"', quote_char)

    result = parser.read_csv(StringIO(new_data), quotechar=quote_char)
    tm.assert_frame_equal(result, expected)


@pytest.mark.parametrize("quoting", [csv.QUOTE_MINIMAL, csv.QUOTE_NONE])
@pytest.mark.parametrize("quote_char", ["", None])
def test_null_quote_char(all_parsers, quoting, quote_char):
    kwargs = dict(quotechar=quote_char, quoting=quoting)
    data = "a,b,c\n1,2,3"
    parser = all_parsers

    if quoting != csv.QUOTE_NONE:
        # Sanity checking.
        msg = "quotechar must be set if quoting enabled"

        with pytest.raises(TypeError, match=msg):
            parser.read_csv(StringIO(data), **kwargs)
    else:
        expected = DataFrame([[1, 2, 3]], columns=["a", "b", "c"])
        result = parser.read_csv(StringIO(data), **kwargs)
        tm.assert_frame_equal(result, expected)


@pytest.mark.parametrize("kwargs,exp_data", [
    (dict(), [[1, 2, "foo"]]),  # Test default.

    # QUOTE_MINIMAL only applies to CSV writing, so no effect on reading.
    (dict(quotechar='"', quoting=csv.QUOTE_MINIMAL), [[1, 2, "foo"]]),

    # QUOTE_MINIMAL only applies to CSV writing, so no effect on reading.
    (dict(quotechar='"', quoting=csv.QUOTE_ALL), [[1, 2, "foo"]]),

    # QUOTE_NONE tells the reader to do no special handling
    # of quote characters and leave them alone.
    (dict(quotechar='"', quoting=csv.QUOTE_NONE), [[1, 2, '"foo"']]),

    # QUOTE_NONNUMERIC tells the reader to cast
    # all non-quoted fields to float
    (dict(quotechar='"', quoting=csv.QUOTE_NONNUMERIC), [[1.0, 2.0, "foo"]])
])
def test_quoting_various(all_parsers, kwargs, exp_data):
    data = '1,2,"foo"'
    parser = all_parsers
    columns = ["a", "b", "c"]

    result = parser.read_csv(StringIO(data), names=columns, **kwargs)
    expected = DataFrame(exp_data, columns=columns)
    tm.assert_frame_equal(result, expected)


@pytest.mark.parametrize("doublequote,exp_data", [
    (True, [[3, '4 " 5']]),
    (False, [[3, '4 " 5"']]),
])
def test_double_quote(all_parsers, doublequote, exp_data):
    parser = all_parsers
    data = 'a,b\n3,"4 "" 5"'

    result = parser.read_csv(StringIO(data), quotechar='"',
                             doublequote=doublequote)
    expected = DataFrame(exp_data, columns=["a", "b"])
    tm.assert_frame_equal(result, expected)


@pytest.mark.parametrize("quotechar", [
    u('"'),
    pytest.param(u('\u0001'), marks=pytest.mark.skipif(
        PY2, reason="Python 2.x does not handle unicode well."))])
def test_quotechar_unicode(all_parsers, quotechar):
    # see gh-14477
    data = "a\n1"
    parser = all_parsers
    expected = DataFrame({"a": [1]})

    result = parser.read_csv(StringIO(data), quotechar=quotechar)
    tm.assert_frame_equal(result, expected)


@pytest.mark.parametrize("balanced", [True, False])
def test_unbalanced_quoting(all_parsers, balanced):
    # see gh-22789.
    parser = all_parsers
    data = "a,b,c\n1,2,\"3"

    if balanced:
        # Re-balance the quoting and read in without errors.
        expected = DataFrame([[1, 2, 3]], columns=["a", "b", "c"])
        result = parser.read_csv(StringIO(data + '"'))
        tm.assert_frame_equal(result, expected)
    else:
        msg = ("EOF inside string starting at row 1" if parser.engine == "c"
               else "unexpected end of data")

        with pytest.raises(ParserError, match=msg):
            parser.read_csv(StringIO(data))