laywerrobot/lib/python3.6/site-packages/pandas/tests/io/parser/test_textreader.py
2020-08-27 21:55:39 +02:00

354 lines
11 KiB
Python

# -*- coding: utf-8 -*-
"""
Tests the TextReader class in parsers.pyx, which
is integral to the C engine in parsers.py
"""
import pytest
from pandas.compat import StringIO, BytesIO, map
from pandas import compat
import os
import sys
from numpy import nan
import numpy as np
from pandas import DataFrame
from pandas.io.parsers import (read_csv, TextFileReader)
from pandas.util.testing import assert_frame_equal
import pandas.util.testing as tm
from pandas._libs.parsers import TextReader
import pandas._libs.parsers as parser
class TestTextReader(object):
@pytest.fixture(autouse=True)
def setup_method(self, datapath):
self.dirpath = datapath('io', 'parser', 'data')
self.csv1 = os.path.join(self.dirpath, 'test1.csv')
self.csv2 = os.path.join(self.dirpath, 'test2.csv')
self.xls1 = os.path.join(self.dirpath, 'test.xls')
def test_file_handle(self):
with open(self.csv1, 'rb') as f:
reader = TextReader(f)
reader.read()
def test_string_filename(self):
reader = TextReader(self.csv1, header=None)
reader.read()
def test_file_handle_mmap(self):
with open(self.csv1, 'rb') as f:
reader = TextReader(f, memory_map=True, header=None)
reader.read()
def test_StringIO(self):
with open(self.csv1, 'rb') as f:
text = f.read()
src = BytesIO(text)
reader = TextReader(src, header=None)
reader.read()
def test_string_factorize(self):
# should this be optional?
data = 'a\nb\na\nb\na'
reader = TextReader(StringIO(data), header=None)
result = reader.read()
assert len(set(map(id, result[0]))) == 2
def test_skipinitialspace(self):
data = ('a, b\n'
'a, b\n'
'a, b\n'
'a, b')
reader = TextReader(StringIO(data), skipinitialspace=True,
header=None)
result = reader.read()
tm.assert_numpy_array_equal(result[0], np.array(['a', 'a', 'a', 'a'],
dtype=np.object_))
tm.assert_numpy_array_equal(result[1], np.array(['b', 'b', 'b', 'b'],
dtype=np.object_))
def test_parse_booleans(self):
data = 'True\nFalse\nTrue\nTrue'
reader = TextReader(StringIO(data), header=None)
result = reader.read()
assert result[0].dtype == np.bool_
def test_delimit_whitespace(self):
data = 'a b\na\t\t "b"\n"a"\t \t b'
reader = TextReader(StringIO(data), delim_whitespace=True,
header=None)
result = reader.read()
tm.assert_numpy_array_equal(result[0], np.array(['a', 'a', 'a'],
dtype=np.object_))
tm.assert_numpy_array_equal(result[1], np.array(['b', 'b', 'b'],
dtype=np.object_))
def test_embedded_newline(self):
data = 'a\n"hello\nthere"\nthis'
reader = TextReader(StringIO(data), header=None)
result = reader.read()
expected = np.array(['a', 'hello\nthere', 'this'], dtype=np.object_)
tm.assert_numpy_array_equal(result[0], expected)
def test_euro_decimal(self):
data = '12345,67\n345,678'
reader = TextReader(StringIO(data), delimiter=':',
decimal=',', header=None)
result = reader.read()
expected = np.array([12345.67, 345.678])
tm.assert_almost_equal(result[0], expected)
def test_integer_thousands(self):
data = '123,456\n12,500'
reader = TextReader(StringIO(data), delimiter=':',
thousands=',', header=None)
result = reader.read()
expected = np.array([123456, 12500], dtype=np.int64)
tm.assert_almost_equal(result[0], expected)
def test_integer_thousands_alt(self):
data = '123.456\n12.500'
reader = TextFileReader(StringIO(data), delimiter=':',
thousands='.', header=None)
result = reader.read()
expected = DataFrame([123456, 12500])
tm.assert_frame_equal(result, expected)
@tm.capture_stderr
def test_skip_bad_lines(self):
# too many lines, see #2430 for why
data = ('a:b:c\n'
'd:e:f\n'
'g:h:i\n'
'j:k:l:m\n'
'l:m:n\n'
'o:p:q:r')
reader = TextReader(StringIO(data), delimiter=':',
header=None)
pytest.raises(parser.ParserError, reader.read)
reader = TextReader(StringIO(data), delimiter=':',
header=None,
error_bad_lines=False,
warn_bad_lines=False)
result = reader.read()
expected = {0: np.array(['a', 'd', 'g', 'l'], dtype=object),
1: np.array(['b', 'e', 'h', 'm'], dtype=object),
2: np.array(['c', 'f', 'i', 'n'], dtype=object)}
assert_array_dicts_equal(result, expected)
reader = TextReader(StringIO(data), delimiter=':',
header=None,
error_bad_lines=False,
warn_bad_lines=True)
reader.read()
val = sys.stderr.getvalue()
assert 'Skipping line 4' in val
assert 'Skipping line 6' in val
def test_header_not_enough_lines(self):
data = ('skip this\n'
'skip this\n'
'a,b,c\n'
'1,2,3\n'
'4,5,6')
reader = TextReader(StringIO(data), delimiter=',', header=2)
header = reader.header
expected = [['a', 'b', 'c']]
assert header == expected
recs = reader.read()
expected = {0: np.array([1, 4], dtype=np.int64),
1: np.array([2, 5], dtype=np.int64),
2: np.array([3, 6], dtype=np.int64)}
assert_array_dicts_equal(recs, expected)
def test_escapechar(self):
data = ('\\"hello world\"\n'
'\\"hello world\"\n'
'\\"hello world\"')
reader = TextReader(StringIO(data), delimiter=',', header=None,
escapechar='\\')
result = reader.read()
expected = {0: np.array(['"hello world"'] * 3, dtype=object)}
assert_array_dicts_equal(result, expected)
def test_eof_has_eol(self):
# handling of new line at EOF
pass
def test_na_substitution(self):
pass
def test_numpy_string_dtype(self):
data = """\
a,1
aa,2
aaa,3
aaaa,4
aaaaa,5"""
def _make_reader(**kwds):
return TextReader(StringIO(data), delimiter=',', header=None,
**kwds)
reader = _make_reader(dtype='S5,i4')
result = reader.read()
assert result[0].dtype == 'S5'
ex_values = np.array(['a', 'aa', 'aaa', 'aaaa', 'aaaaa'], dtype='S5')
assert (result[0] == ex_values).all()
assert result[1].dtype == 'i4'
reader = _make_reader(dtype='S4')
result = reader.read()
assert result[0].dtype == 'S4'
ex_values = np.array(['a', 'aa', 'aaa', 'aaaa', 'aaaa'], dtype='S4')
assert (result[0] == ex_values).all()
assert result[1].dtype == 'S4'
def test_pass_dtype(self):
data = """\
one,two
1,a
2,b
3,c
4,d"""
def _make_reader(**kwds):
return TextReader(StringIO(data), delimiter=',', **kwds)
reader = _make_reader(dtype={'one': 'u1', 1: 'S1'})
result = reader.read()
assert result[0].dtype == 'u1'
assert result[1].dtype == 'S1'
reader = _make_reader(dtype={'one': np.uint8, 1: object})
result = reader.read()
assert result[0].dtype == 'u1'
assert result[1].dtype == 'O'
reader = _make_reader(dtype={'one': np.dtype('u1'),
1: np.dtype('O')})
result = reader.read()
assert result[0].dtype == 'u1'
assert result[1].dtype == 'O'
def test_usecols(self):
data = """\
a,b,c
1,2,3
4,5,6
7,8,9
10,11,12"""
def _make_reader(**kwds):
return TextReader(StringIO(data), delimiter=',', **kwds)
reader = _make_reader(usecols=(1, 2))
result = reader.read()
exp = _make_reader().read()
assert len(result) == 2
assert (result[1] == exp[1]).all()
assert (result[2] == exp[2]).all()
def test_cr_delimited(self):
def _test(text, **kwargs):
nice_text = text.replace('\r', '\r\n')
result = TextReader(StringIO(text), **kwargs).read()
expected = TextReader(StringIO(nice_text), **kwargs).read()
assert_array_dicts_equal(result, expected)
data = 'a,b,c\r1,2,3\r4,5,6\r7,8,9\r10,11,12'
_test(data, delimiter=',')
data = 'a b c\r1 2 3\r4 5 6\r7 8 9\r10 11 12'
_test(data, delim_whitespace=True)
data = 'a,b,c\r1,2,3\r4,5,6\r,88,9\r10,11,12'
_test(data, delimiter=',')
sample = ('A,B,C,D,E,F,G,H,I,J,K,L,M,N,O\r'
'AAAAA,BBBBB,0,0,0,0,0,0,0,0,0,0,0,0,0\r'
',BBBBB,0,0,0,0,0,0,0,0,0,0,0,0,0')
_test(sample, delimiter=',')
data = 'A B C\r 2 3\r4 5 6'
_test(data, delim_whitespace=True)
data = 'A B C\r2 3\r4 5 6'
_test(data, delim_whitespace=True)
def test_empty_field_eof(self):
data = 'a,b,c\n1,2,3\n4,,'
result = TextReader(StringIO(data), delimiter=',').read()
expected = {0: np.array([1, 4], dtype=np.int64),
1: np.array(['2', ''], dtype=object),
2: np.array(['3', ''], dtype=object)}
assert_array_dicts_equal(result, expected)
# GH5664
a = DataFrame([['b'], [nan]], columns=['a'], index=['a', 'c'])
b = DataFrame([[1, 1, 1, 0], [1, 1, 1, 0]],
columns=list('abcd'),
index=[1, 1])
c = DataFrame([[1, 2, 3, 4], [6, nan, nan, nan],
[8, 9, 10, 11], [13, 14, nan, nan]],
columns=list('abcd'),
index=[0, 5, 7, 12])
for _ in range(100):
df = read_csv(StringIO('a,b\nc\n'), skiprows=0,
names=['a'], engine='c')
assert_frame_equal(df, a)
df = read_csv(StringIO('1,1,1,1,0\n' * 2 + '\n' * 2),
names=list("abcd"), engine='c')
assert_frame_equal(df, b)
df = read_csv(StringIO('0,1,2,3,4\n5,6\n7,8,9,10,11\n12,13,14'),
names=list('abcd'), engine='c')
assert_frame_equal(df, c)
def test_empty_csv_input(self):
# GH14867
df = read_csv(StringIO(), chunksize=20, header=None,
names=['a', 'b', 'c'])
assert isinstance(df, TextFileReader)
def assert_array_dicts_equal(left, right):
for k, v in compat.iteritems(left):
assert tm.assert_numpy_array_equal(np.asarray(v),
np.asarray(right[k]))