laywerrobot/lib/python3.6/site-packages/pandas/tests/frame/test_to_csv.py

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2020-08-27 21:55:39 +02:00
# -*- coding: utf-8 -*-
from __future__ import print_function
import csv
import pytest
from numpy import nan
import numpy as np
from pandas.compat import (lmap, range, lrange, StringIO, u)
from pandas.io.common import _get_handle
import pandas.core.common as com
from pandas.errors import ParserError
from pandas import (DataFrame, Index, Series, MultiIndex, Timestamp,
date_range, read_csv, compat, to_datetime)
import pandas as pd
from pandas.util.testing import (assert_almost_equal,
assert_series_equal,
assert_frame_equal,
ensure_clean,
makeCustomDataframe as mkdf)
import pandas.util.testing as tm
from pandas.tests.frame.common import TestData
MIXED_FLOAT_DTYPES = ['float16', 'float32', 'float64']
MIXED_INT_DTYPES = ['uint8', 'uint16', 'uint32', 'uint64', 'int8', 'int16',
'int32', 'int64']
class TestDataFrameToCSV(TestData):
def read_csv(self, path, **kwargs):
params = dict(index_col=0, parse_dates=True)
params.update(**kwargs)
return pd.read_csv(path, **params)
def test_from_csv_deprecation(self):
# see gh-17812
with ensure_clean('__tmp_from_csv_deprecation__') as path:
self.tsframe.to_csv(path)
with tm.assert_produces_warning(FutureWarning):
depr_recons = DataFrame.from_csv(path)
assert_frame_equal(self.tsframe, depr_recons)
def test_to_csv_from_csv1(self):
with ensure_clean('__tmp_to_csv_from_csv1__') as path:
self.frame['A'][:5] = nan
self.frame.to_csv(path)
self.frame.to_csv(path, columns=['A', 'B'])
self.frame.to_csv(path, header=False)
self.frame.to_csv(path, index=False)
# test roundtrip
self.tsframe.to_csv(path)
recons = self.read_csv(path)
assert_frame_equal(self.tsframe, recons)
self.tsframe.to_csv(path, index_label='index')
recons = self.read_csv(path, index_col=None)
assert(len(recons.columns) == len(self.tsframe.columns) + 1)
# no index
self.tsframe.to_csv(path, index=False)
recons = self.read_csv(path, index_col=None)
assert_almost_equal(self.tsframe.values, recons.values)
# corner case
dm = DataFrame({'s1': Series(lrange(3), lrange(3)),
's2': Series(lrange(2), lrange(2))})
dm.to_csv(path)
recons = self.read_csv(path)
assert_frame_equal(dm, recons)
def test_to_csv_from_csv2(self):
with ensure_clean('__tmp_to_csv_from_csv2__') as path:
# duplicate index
df = DataFrame(np.random.randn(3, 3), index=['a', 'a', 'b'],
columns=['x', 'y', 'z'])
df.to_csv(path)
result = self.read_csv(path)
assert_frame_equal(result, df)
midx = MultiIndex.from_tuples(
[('A', 1, 2), ('A', 1, 2), ('B', 1, 2)])
df = DataFrame(np.random.randn(3, 3), index=midx,
columns=['x', 'y', 'z'])
df.to_csv(path)
result = self.read_csv(path, index_col=[0, 1, 2],
parse_dates=False)
assert_frame_equal(result, df, check_names=False)
# column aliases
col_aliases = Index(['AA', 'X', 'Y', 'Z'])
self.frame2.to_csv(path, header=col_aliases)
rs = self.read_csv(path)
xp = self.frame2.copy()
xp.columns = col_aliases
assert_frame_equal(xp, rs)
pytest.raises(ValueError, self.frame2.to_csv, path,
header=['AA', 'X'])
def test_to_csv_from_csv3(self):
with ensure_clean('__tmp_to_csv_from_csv3__') as path:
df1 = DataFrame(np.random.randn(3, 1))
df2 = DataFrame(np.random.randn(3, 1))
df1.to_csv(path)
df2.to_csv(path, mode='a', header=False)
xp = pd.concat([df1, df2])
rs = pd.read_csv(path, index_col=0)
rs.columns = lmap(int, rs.columns)
xp.columns = lmap(int, xp.columns)
assert_frame_equal(xp, rs)
def test_to_csv_from_csv4(self):
with ensure_clean('__tmp_to_csv_from_csv4__') as path:
# GH 10833 (TimedeltaIndex formatting)
dt = pd.Timedelta(seconds=1)
df = pd.DataFrame({'dt_data': [i * dt for i in range(3)]},
index=pd.Index([i * dt for i in range(3)],
name='dt_index'))
df.to_csv(path)
result = pd.read_csv(path, index_col='dt_index')
result.index = pd.to_timedelta(result.index)
# TODO: remove renaming when GH 10875 is solved
result.index = result.index.rename('dt_index')
result['dt_data'] = pd.to_timedelta(result['dt_data'])
assert_frame_equal(df, result, check_index_type=True)
def test_to_csv_from_csv5(self):
# tz, 8260
with ensure_clean('__tmp_to_csv_from_csv5__') as path:
self.tzframe.to_csv(path)
result = pd.read_csv(path, index_col=0, parse_dates=['A'])
converter = lambda c: to_datetime(result[c]).dt.tz_localize(
'UTC').dt.tz_convert(self.tzframe[c].dt.tz)
result['B'] = converter('B')
result['C'] = converter('C')
assert_frame_equal(result, self.tzframe)
def test_to_csv_cols_reordering(self):
# GH3454
import pandas as pd
chunksize = 5
N = int(chunksize * 2.5)
df = mkdf(N, 3)
cs = df.columns
cols = [cs[2], cs[0]]
with ensure_clean() as path:
df.to_csv(path, columns=cols, chunksize=chunksize)
rs_c = pd.read_csv(path, index_col=0)
assert_frame_equal(df[cols], rs_c, check_names=False)
def test_to_csv_new_dupe_cols(self):
import pandas as pd
def _check_df(df, cols=None):
with ensure_clean() as path:
df.to_csv(path, columns=cols, chunksize=chunksize)
rs_c = pd.read_csv(path, index_col=0)
# we wrote them in a different order
# so compare them in that order
if cols is not None:
if df.columns.is_unique:
rs_c.columns = cols
else:
indexer, missing = df.columns.get_indexer_non_unique(
cols)
rs_c.columns = df.columns.take(indexer)
for c in cols:
obj_df = df[c]
obj_rs = rs_c[c]
if isinstance(obj_df, Series):
assert_series_equal(obj_df, obj_rs)
else:
assert_frame_equal(
obj_df, obj_rs, check_names=False)
# wrote in the same order
else:
rs_c.columns = df.columns
assert_frame_equal(df, rs_c, check_names=False)
chunksize = 5
N = int(chunksize * 2.5)
# dupe cols
df = mkdf(N, 3)
df.columns = ['a', 'a', 'b']
_check_df(df, None)
# dupe cols with selection
cols = ['b', 'a']
_check_df(df, cols)
@pytest.mark.slow
def test_to_csv_dtnat(self):
# GH3437
from pandas import NaT
def make_dtnat_arr(n, nnat=None):
if nnat is None:
nnat = int(n * 0.1) # 10%
s = list(date_range('2000', freq='5min', periods=n))
if nnat:
for i in np.random.randint(0, len(s), nnat):
s[i] = NaT
i = np.random.randint(100)
s[-i] = NaT
s[i] = NaT
return s
chunksize = 1000
# N=35000
s1 = make_dtnat_arr(chunksize + 5)
s2 = make_dtnat_arr(chunksize + 5, 0)
# s3=make_dtnjat_arr(chunksize+5,0)
with ensure_clean('1.csv') as pth:
df = DataFrame(dict(a=s1, b=s2))
df.to_csv(pth, chunksize=chunksize)
recons = self.read_csv(pth)._convert(datetime=True,
coerce=True)
assert_frame_equal(df, recons, check_names=False,
check_less_precise=True)
@pytest.mark.slow
def test_to_csv_moar(self):
def _do_test(df, r_dtype=None, c_dtype=None,
rnlvl=None, cnlvl=None, dupe_col=False):
kwargs = dict(parse_dates=False)
if cnlvl:
if rnlvl is not None:
kwargs['index_col'] = lrange(rnlvl)
kwargs['header'] = lrange(cnlvl)
with ensure_clean('__tmp_to_csv_moar__') as path:
df.to_csv(path, encoding='utf8',
chunksize=chunksize)
recons = self.read_csv(path, **kwargs)
else:
kwargs['header'] = 0
with ensure_clean('__tmp_to_csv_moar__') as path:
df.to_csv(path, encoding='utf8', chunksize=chunksize)
recons = self.read_csv(path, **kwargs)
def _to_uni(x):
if not isinstance(x, compat.text_type):
return x.decode('utf8')
return x
if dupe_col:
# read_Csv disambiguates the columns by
# labeling them dupe.1,dupe.2, etc'. monkey patch columns
recons.columns = df.columns
if rnlvl and not cnlvl:
delta_lvl = [recons.iloc[
:, i].values for i in range(rnlvl - 1)]
ix = MultiIndex.from_arrays([list(recons.index)] + delta_lvl)
recons.index = ix
recons = recons.iloc[:, rnlvl - 1:]
type_map = dict(i='i', f='f', s='O', u='O', dt='O', p='O')
if r_dtype:
if r_dtype == 'u': # unicode
r_dtype = 'O'
recons.index = np.array(lmap(_to_uni, recons.index),
dtype=r_dtype)
df.index = np.array(lmap(_to_uni, df.index), dtype=r_dtype)
elif r_dtype == 'dt': # unicode
r_dtype = 'O'
recons.index = np.array(lmap(Timestamp, recons.index),
dtype=r_dtype)
df.index = np.array(
lmap(Timestamp, df.index), dtype=r_dtype)
elif r_dtype == 'p':
r_dtype = 'O'
recons.index = np.array(
list(map(Timestamp, to_datetime(recons.index))),
dtype=r_dtype)
df.index = np.array(
list(map(Timestamp, df.index.to_timestamp())),
dtype=r_dtype)
else:
r_dtype = type_map.get(r_dtype)
recons.index = np.array(recons.index, dtype=r_dtype)
df.index = np.array(df.index, dtype=r_dtype)
if c_dtype:
if c_dtype == 'u':
c_dtype = 'O'
recons.columns = np.array(lmap(_to_uni, recons.columns),
dtype=c_dtype)
df.columns = np.array(
lmap(_to_uni, df.columns), dtype=c_dtype)
elif c_dtype == 'dt':
c_dtype = 'O'
recons.columns = np.array(lmap(Timestamp, recons.columns),
dtype=c_dtype)
df.columns = np.array(
lmap(Timestamp, df.columns), dtype=c_dtype)
elif c_dtype == 'p':
c_dtype = 'O'
recons.columns = np.array(
lmap(Timestamp, to_datetime(recons.columns)),
dtype=c_dtype)
df.columns = np.array(
lmap(Timestamp, df.columns.to_timestamp()),
dtype=c_dtype)
else:
c_dtype = type_map.get(c_dtype)
recons.columns = np.array(recons.columns, dtype=c_dtype)
df.columns = np.array(df.columns, dtype=c_dtype)
assert_frame_equal(df, recons, check_names=False,
check_less_precise=True)
N = 100
chunksize = 1000
for ncols in [4]:
base = int((chunksize // ncols or 1) or 1)
for nrows in [2, 10, N - 1, N, N + 1, N + 2, 2 * N - 2,
2 * N - 1, 2 * N, 2 * N + 1, 2 * N + 2,
base - 1, base, base + 1]:
_do_test(mkdf(nrows, ncols, r_idx_type='dt',
c_idx_type='s'), 'dt', 's')
for ncols in [4]:
base = int((chunksize // ncols or 1) or 1)
for nrows in [2, 10, N - 1, N, N + 1, N + 2, 2 * N - 2,
2 * N - 1, 2 * N, 2 * N + 1, 2 * N + 2,
base - 1, base, base + 1]:
_do_test(mkdf(nrows, ncols, r_idx_type='dt',
c_idx_type='s'), 'dt', 's')
pass
for r_idx_type, c_idx_type in [('i', 'i'), ('s', 's'), ('u', 'dt'),
('p', 'p')]:
for ncols in [1, 2, 3, 4]:
base = int((chunksize // ncols or 1) or 1)
for nrows in [2, 10, N - 1, N, N + 1, N + 2, 2 * N - 2,
2 * N - 1, 2 * N, 2 * N + 1, 2 * N + 2,
base - 1, base, base + 1]:
_do_test(mkdf(nrows, ncols, r_idx_type=r_idx_type,
c_idx_type=c_idx_type),
r_idx_type, c_idx_type)
for ncols in [1, 2, 3, 4]:
base = int((chunksize // ncols or 1) or 1)
for nrows in [10, N - 2, N - 1, N, N + 1, N + 2, 2 * N - 2,
2 * N - 1, 2 * N, 2 * N + 1, 2 * N + 2,
base - 1, base, base + 1]:
_do_test(mkdf(nrows, ncols))
for nrows in [10, N - 2, N - 1, N, N + 1, N + 2]:
df = mkdf(nrows, 3)
cols = list(df.columns)
cols[:2] = ["dupe", "dupe"]
cols[-2:] = ["dupe", "dupe"]
ix = list(df.index)
ix[:2] = ["rdupe", "rdupe"]
ix[-2:] = ["rdupe", "rdupe"]
df.index = ix
df.columns = cols
_do_test(df, dupe_col=True)
_do_test(DataFrame(index=lrange(10)))
_do_test(mkdf(chunksize // 2 + 1, 2, r_idx_nlevels=2), rnlvl=2)
for ncols in [2, 3, 4]:
base = int(chunksize // ncols)
for nrows in [10, N - 2, N - 1, N, N + 1, N + 2, 2 * N - 2,
2 * N - 1, 2 * N, 2 * N + 1, 2 * N + 2,
base - 1, base, base + 1]:
_do_test(mkdf(nrows, ncols, r_idx_nlevels=2), rnlvl=2)
_do_test(mkdf(nrows, ncols, c_idx_nlevels=2), cnlvl=2)
_do_test(mkdf(nrows, ncols, r_idx_nlevels=2, c_idx_nlevels=2),
rnlvl=2, cnlvl=2)
def test_to_csv_from_csv_w_some_infs(self):
# test roundtrip with inf, -inf, nan, as full columns and mix
self.frame['G'] = np.nan
f = lambda x: [np.inf, np.nan][np.random.rand() < .5]
self.frame['H'] = self.frame.index.map(f)
with ensure_clean() as path:
self.frame.to_csv(path)
recons = self.read_csv(path)
# TODO to_csv drops column name
assert_frame_equal(self.frame, recons, check_names=False)
assert_frame_equal(np.isinf(self.frame),
np.isinf(recons), check_names=False)
def test_to_csv_from_csv_w_all_infs(self):
# test roundtrip with inf, -inf, nan, as full columns and mix
self.frame['E'] = np.inf
self.frame['F'] = -np.inf
with ensure_clean() as path:
self.frame.to_csv(path)
recons = self.read_csv(path)
# TODO to_csv drops column name
assert_frame_equal(self.frame, recons, check_names=False)
assert_frame_equal(np.isinf(self.frame),
np.isinf(recons), check_names=False)
def test_to_csv_no_index(self):
# GH 3624, after appending columns, to_csv fails
with ensure_clean('__tmp_to_csv_no_index__') as path:
df = DataFrame({'c1': [1, 2, 3], 'c2': [4, 5, 6]})
df.to_csv(path, index=False)
result = read_csv(path)
assert_frame_equal(df, result)
df['c3'] = Series([7, 8, 9], dtype='int64')
df.to_csv(path, index=False)
result = read_csv(path)
assert_frame_equal(df, result)
def test_to_csv_with_mix_columns(self):
# gh-11637: incorrect output when a mix of integer and string column
# names passed as columns parameter in to_csv
df = DataFrame({0: ['a', 'b', 'c'],
1: ['aa', 'bb', 'cc']})
df['test'] = 'txt'
assert df.to_csv() == df.to_csv(columns=[0, 1, 'test'])
def test_to_csv_headers(self):
# GH6186, the presence or absence of `index` incorrectly
# causes to_csv to have different header semantics.
from_df = DataFrame([[1, 2], [3, 4]], columns=['A', 'B'])
to_df = DataFrame([[1, 2], [3, 4]], columns=['X', 'Y'])
with ensure_clean('__tmp_to_csv_headers__') as path:
from_df.to_csv(path, header=['X', 'Y'])
recons = self.read_csv(path)
assert_frame_equal(to_df, recons)
from_df.to_csv(path, index=False, header=['X', 'Y'])
recons = self.read_csv(path)
recons.reset_index(inplace=True)
assert_frame_equal(to_df, recons)
def test_to_csv_multiindex(self):
frame = self.frame
old_index = frame.index
arrays = np.arange(len(old_index) * 2).reshape(2, -1)
new_index = MultiIndex.from_arrays(arrays, names=['first', 'second'])
frame.index = new_index
with ensure_clean('__tmp_to_csv_multiindex__') as path:
frame.to_csv(path, header=False)
frame.to_csv(path, columns=['A', 'B'])
# round trip
frame.to_csv(path)
df = self.read_csv(path, index_col=[0, 1],
parse_dates=False)
# TODO to_csv drops column name
assert_frame_equal(frame, df, check_names=False)
assert frame.index.names == df.index.names
# needed if setUp becomes a class method
self.frame.index = old_index
# try multiindex with dates
tsframe = self.tsframe
old_index = tsframe.index
new_index = [old_index, np.arange(len(old_index))]
tsframe.index = MultiIndex.from_arrays(new_index)
tsframe.to_csv(path, index_label=['time', 'foo'])
recons = self.read_csv(path, index_col=[0, 1])
# TODO to_csv drops column name
assert_frame_equal(tsframe, recons, check_names=False)
# do not load index
tsframe.to_csv(path)
recons = self.read_csv(path, index_col=None)
assert len(recons.columns) == len(tsframe.columns) + 2
# no index
tsframe.to_csv(path, index=False)
recons = self.read_csv(path, index_col=None)
assert_almost_equal(recons.values, self.tsframe.values)
# needed if setUp becomes class method
self.tsframe.index = old_index
with ensure_clean('__tmp_to_csv_multiindex__') as path:
# GH3571, GH1651, GH3141
def _make_frame(names=None):
if names is True:
names = ['first', 'second']
return DataFrame(np.random.randint(0, 10, size=(3, 3)),
columns=MultiIndex.from_tuples(
[('bah', 'foo'),
('bah', 'bar'),
('ban', 'baz')], names=names),
dtype='int64')
# column & index are multi-index
df = mkdf(5, 3, r_idx_nlevels=2, c_idx_nlevels=4)
df.to_csv(path)
result = read_csv(path, header=[0, 1, 2, 3],
index_col=[0, 1])
assert_frame_equal(df, result)
# column is mi
df = mkdf(5, 3, r_idx_nlevels=1, c_idx_nlevels=4)
df.to_csv(path)
result = read_csv(
path, header=[0, 1, 2, 3], index_col=0)
assert_frame_equal(df, result)
# dup column names?
df = mkdf(5, 3, r_idx_nlevels=3, c_idx_nlevels=4)
df.to_csv(path)
result = read_csv(path, header=[0, 1, 2, 3],
index_col=[0, 1, 2])
assert_frame_equal(df, result)
# writing with no index
df = _make_frame()
df.to_csv(path, index=False)
result = read_csv(path, header=[0, 1])
assert_frame_equal(df, result)
# we lose the names here
df = _make_frame(True)
df.to_csv(path, index=False)
result = read_csv(path, header=[0, 1])
assert com._all_none(*result.columns.names)
result.columns.names = df.columns.names
assert_frame_equal(df, result)
# tupleize_cols=True and index=False
df = _make_frame(True)
with tm.assert_produces_warning(FutureWarning):
df.to_csv(path, tupleize_cols=True, index=False)
with tm.assert_produces_warning(FutureWarning,
check_stacklevel=False):
result = read_csv(path, header=0,
tupleize_cols=True,
index_col=None)
result.columns = df.columns
assert_frame_equal(df, result)
# whatsnew example
df = _make_frame()
df.to_csv(path)
result = read_csv(path, header=[0, 1],
index_col=[0])
assert_frame_equal(df, result)
df = _make_frame(True)
df.to_csv(path)
result = read_csv(path, header=[0, 1],
index_col=[0])
assert_frame_equal(df, result)
# column & index are multi-index (compatibility)
df = mkdf(5, 3, r_idx_nlevels=2, c_idx_nlevels=4)
with tm.assert_produces_warning(FutureWarning):
df.to_csv(path, tupleize_cols=True)
with tm.assert_produces_warning(FutureWarning,
check_stacklevel=False):
result = read_csv(path, header=0, index_col=[0, 1],
tupleize_cols=True)
result.columns = df.columns
assert_frame_equal(df, result)
# invalid options
df = _make_frame(True)
df.to_csv(path)
for i in [6, 7]:
msg = 'len of {i}, but only 5 lines in file'.format(i=i)
with tm.assert_raises_regex(ParserError, msg):
read_csv(path, header=lrange(i), index_col=0)
# write with cols
with tm.assert_raises_regex(TypeError, 'cannot specify cols '
'with a MultiIndex'):
df.to_csv(path, columns=['foo', 'bar'])
with ensure_clean('__tmp_to_csv_multiindex__') as path:
# empty
tsframe[:0].to_csv(path)
recons = self.read_csv(path)
exp = tsframe[:0]
exp.index = []
tm.assert_index_equal(recons.columns, exp.columns)
assert len(recons) == 0
def test_to_csv_float32_nanrep(self):
df = DataFrame(np.random.randn(1, 4).astype(np.float32))
df[1] = np.nan
with ensure_clean('__tmp_to_csv_float32_nanrep__.csv') as path:
df.to_csv(path, na_rep=999)
with open(path) as f:
lines = f.readlines()
assert lines[1].split(',')[2] == '999'
def test_to_csv_withcommas(self):
# Commas inside fields should be correctly escaped when saving as CSV.
df = DataFrame({'A': [1, 2, 3], 'B': ['5,6', '7,8', '9,0']})
with ensure_clean('__tmp_to_csv_withcommas__.csv') as path:
df.to_csv(path)
df2 = self.read_csv(path)
assert_frame_equal(df2, df)
def test_to_csv_mixed(self):
def create_cols(name):
return ["%s%03d" % (name, i) for i in range(5)]
df_float = DataFrame(np.random.randn(
100, 5), dtype='float64', columns=create_cols('float'))
df_int = DataFrame(np.random.randn(100, 5),
dtype='int64', columns=create_cols('int'))
df_bool = DataFrame(True, index=df_float.index,
columns=create_cols('bool'))
df_object = DataFrame('foo', index=df_float.index,
columns=create_cols('object'))
df_dt = DataFrame(Timestamp('20010101'),
index=df_float.index, columns=create_cols('date'))
# add in some nans
df_float.loc[30:50, 1:3] = np.nan
# ## this is a bug in read_csv right now ####
# df_dt.loc[30:50,1:3] = np.nan
df = pd.concat([df_float, df_int, df_bool, df_object, df_dt], axis=1)
# dtype
dtypes = dict()
for n, dtype in [('float', np.float64), ('int', np.int64),
('bool', np.bool), ('object', np.object)]:
for c in create_cols(n):
dtypes[c] = dtype
with ensure_clean() as filename:
df.to_csv(filename)
rs = read_csv(filename, index_col=0, dtype=dtypes,
parse_dates=create_cols('date'))
assert_frame_equal(rs, df)
def test_to_csv_dups_cols(self):
df = DataFrame(np.random.randn(1000, 30), columns=lrange(
15) + lrange(15), dtype='float64')
with ensure_clean() as filename:
df.to_csv(filename) # single dtype, fine
result = read_csv(filename, index_col=0)
result.columns = df.columns
assert_frame_equal(result, df)
df_float = DataFrame(np.random.randn(1000, 3), dtype='float64')
df_int = DataFrame(np.random.randn(1000, 3), dtype='int64')
df_bool = DataFrame(True, index=df_float.index, columns=lrange(3))
df_object = DataFrame('foo', index=df_float.index, columns=lrange(3))
df_dt = DataFrame(Timestamp('20010101'),
index=df_float.index, columns=lrange(3))
df = pd.concat([df_float, df_int, df_bool, df_object,
df_dt], axis=1, ignore_index=True)
cols = []
for i in range(5):
cols.extend([0, 1, 2])
df.columns = cols
with ensure_clean() as filename:
df.to_csv(filename)
result = read_csv(filename, index_col=0)
# date cols
for i in ['0.4', '1.4', '2.4']:
result[i] = to_datetime(result[i])
result.columns = df.columns
assert_frame_equal(result, df)
# GH3457
from pandas.util.testing import makeCustomDataframe as mkdf
N = 10
df = mkdf(N, 3)
df.columns = ['a', 'a', 'b']
with ensure_clean() as filename:
df.to_csv(filename)
# read_csv will rename the dups columns
result = read_csv(filename, index_col=0)
result = result.rename(columns={'a.1': 'a'})
assert_frame_equal(result, df)
def test_to_csv_chunking(self):
aa = DataFrame({'A': lrange(100000)})
aa['B'] = aa.A + 1.0
aa['C'] = aa.A + 2.0
aa['D'] = aa.A + 3.0
for chunksize in [10000, 50000, 100000]:
with ensure_clean() as filename:
aa.to_csv(filename, chunksize=chunksize)
rs = read_csv(filename, index_col=0)
assert_frame_equal(rs, aa)
@pytest.mark.slow
def test_to_csv_wide_frame_formatting(self):
# Issue #8621
df = DataFrame(np.random.randn(1, 100010), columns=None, index=None)
with ensure_clean() as filename:
df.to_csv(filename, header=False, index=False)
rs = read_csv(filename, header=None)
assert_frame_equal(rs, df)
def test_to_csv_bug(self):
f1 = StringIO('a,1.0\nb,2.0')
df = self.read_csv(f1, header=None)
newdf = DataFrame({'t': df[df.columns[0]]})
with ensure_clean() as path:
newdf.to_csv(path)
recons = read_csv(path, index_col=0)
# don't check_names as t != 1
assert_frame_equal(recons, newdf, check_names=False)
def test_to_csv_unicode(self):
df = DataFrame({u('c/\u03c3'): [1, 2, 3]})
with ensure_clean() as path:
df.to_csv(path, encoding='UTF-8')
df2 = read_csv(path, index_col=0, encoding='UTF-8')
assert_frame_equal(df, df2)
df.to_csv(path, encoding='UTF-8', index=False)
df2 = read_csv(path, index_col=None, encoding='UTF-8')
assert_frame_equal(df, df2)
def test_to_csv_unicode_index_col(self):
buf = StringIO('')
df = DataFrame(
[[u("\u05d0"), "d2", "d3", "d4"], ["a1", "a2", "a3", "a4"]],
columns=[u("\u05d0"),
u("\u05d1"), u("\u05d2"), u("\u05d3")],
index=[u("\u05d0"), u("\u05d1")])
df.to_csv(buf, encoding='UTF-8')
buf.seek(0)
df2 = read_csv(buf, index_col=0, encoding='UTF-8')
assert_frame_equal(df, df2)
def test_to_csv_stringio(self):
buf = StringIO()
self.frame.to_csv(buf)
buf.seek(0)
recons = read_csv(buf, index_col=0)
# TODO to_csv drops column name
assert_frame_equal(recons, self.frame, check_names=False)
def test_to_csv_float_format(self):
df = DataFrame([[0.123456, 0.234567, 0.567567],
[12.32112, 123123.2, 321321.2]],
index=['A', 'B'], columns=['X', 'Y', 'Z'])
with ensure_clean() as filename:
df.to_csv(filename, float_format='%.2f')
rs = read_csv(filename, index_col=0)
xp = DataFrame([[0.12, 0.23, 0.57],
[12.32, 123123.20, 321321.20]],
index=['A', 'B'], columns=['X', 'Y', 'Z'])
assert_frame_equal(rs, xp)
def test_to_csv_unicodewriter_quoting(self):
df = DataFrame({'A': [1, 2, 3], 'B': ['foo', 'bar', 'baz']})
buf = StringIO()
df.to_csv(buf, index=False, quoting=csv.QUOTE_NONNUMERIC,
encoding='utf-8')
result = buf.getvalue()
expected = ('"A","B"\n'
'1,"foo"\n'
'2,"bar"\n'
'3,"baz"\n')
assert result == expected
def test_to_csv_quote_none(self):
# GH4328
df = DataFrame({'A': ['hello', '{"hello"}']})
for encoding in (None, 'utf-8'):
buf = StringIO()
df.to_csv(buf, quoting=csv.QUOTE_NONE,
encoding=encoding, index=False)
result = buf.getvalue()
expected = 'A\nhello\n{"hello"}\n'
assert result == expected
def test_to_csv_index_no_leading_comma(self):
df = DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]},
index=['one', 'two', 'three'])
buf = StringIO()
df.to_csv(buf, index_label=False)
expected = ('A,B\n'
'one,1,4\n'
'two,2,5\n'
'three,3,6\n')
assert buf.getvalue() == expected
def test_to_csv_line_terminators(self):
df = DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]},
index=['one', 'two', 'three'])
buf = StringIO()
df.to_csv(buf, line_terminator='\r\n')
expected = (',A,B\r\n'
'one,1,4\r\n'
'two,2,5\r\n'
'three,3,6\r\n')
assert buf.getvalue() == expected
buf = StringIO()
df.to_csv(buf) # The default line terminator remains \n
expected = (',A,B\n'
'one,1,4\n'
'two,2,5\n'
'three,3,6\n')
assert buf.getvalue() == expected
def test_to_csv_from_csv_categorical(self):
# CSV with categoricals should result in the same output as when one
# would add a "normal" Series/DataFrame.
s = Series(pd.Categorical(['a', 'b', 'b', 'a', 'a', 'c', 'c', 'c']))
s2 = Series(['a', 'b', 'b', 'a', 'a', 'c', 'c', 'c'])
res = StringIO()
s.to_csv(res)
exp = StringIO()
s2.to_csv(exp)
assert res.getvalue() == exp.getvalue()
df = DataFrame({"s": s})
df2 = DataFrame({"s": s2})
res = StringIO()
df.to_csv(res)
exp = StringIO()
df2.to_csv(exp)
assert res.getvalue() == exp.getvalue()
def test_to_csv_path_is_none(self):
# GH 8215
# Make sure we return string for consistency with
# Series.to_csv()
csv_str = self.frame.to_csv(path_or_buf=None)
assert isinstance(csv_str, str)
recons = pd.read_csv(StringIO(csv_str), index_col=0)
assert_frame_equal(self.frame, recons)
@pytest.mark.parametrize('df,encoding', [
(DataFrame([[0.123456, 0.234567, 0.567567],
[12.32112, 123123.2, 321321.2]],
index=['A', 'B'], columns=['X', 'Y', 'Z']), None),
# GH 21241, 21118
(DataFrame([['abc', 'def', 'ghi']], columns=['X', 'Y', 'Z']), 'ascii'),
(DataFrame(5 * [[123, u"你好", u"世界"]],
columns=['X', 'Y', 'Z']), 'gb2312'),
(DataFrame(5 * [[123, u"Γειά σου", u"Κόσμε"]],
columns=['X', 'Y', 'Z']), 'cp737')
])
def test_to_csv_compression(self, df, encoding, compression):
with ensure_clean() as filename:
df.to_csv(filename, compression=compression, encoding=encoding)
# test the round trip - to_csv -> read_csv
result = read_csv(filename, compression=compression,
index_col=0, encoding=encoding)
assert_frame_equal(df, result)
# test the round trip using file handle - to_csv -> read_csv
f, _handles = _get_handle(filename, 'w', compression=compression,
encoding=encoding)
with f:
df.to_csv(f, encoding=encoding)
result = pd.read_csv(filename, compression=compression,
encoding=encoding, index_col=0, squeeze=True)
assert_frame_equal(df, result)
# explicitly make sure file is compressed
with tm.decompress_file(filename, compression) as fh:
text = fh.read().decode(encoding or 'utf8')
for col in df.columns:
assert col in text
with tm.decompress_file(filename, compression) as fh:
assert_frame_equal(df, read_csv(fh,
index_col=0,
encoding=encoding))
def test_to_csv_date_format(self):
with ensure_clean('__tmp_to_csv_date_format__') as path:
dt_index = self.tsframe.index
datetime_frame = DataFrame(
{'A': dt_index, 'B': dt_index.shift(1)}, index=dt_index)
datetime_frame.to_csv(path, date_format='%Y%m%d')
# Check that the data was put in the specified format
test = read_csv(path, index_col=0)
datetime_frame_int = datetime_frame.applymap(
lambda x: int(x.strftime('%Y%m%d')))
datetime_frame_int.index = datetime_frame_int.index.map(
lambda x: int(x.strftime('%Y%m%d')))
assert_frame_equal(test, datetime_frame_int)
datetime_frame.to_csv(path, date_format='%Y-%m-%d')
# Check that the data was put in the specified format
test = read_csv(path, index_col=0)
datetime_frame_str = datetime_frame.applymap(
lambda x: x.strftime('%Y-%m-%d'))
datetime_frame_str.index = datetime_frame_str.index.map(
lambda x: x.strftime('%Y-%m-%d'))
assert_frame_equal(test, datetime_frame_str)
# Check that columns get converted
datetime_frame_columns = datetime_frame.T
datetime_frame_columns.to_csv(path, date_format='%Y%m%d')
test = read_csv(path, index_col=0)
datetime_frame_columns = datetime_frame_columns.applymap(
lambda x: int(x.strftime('%Y%m%d')))
# Columns don't get converted to ints by read_csv
datetime_frame_columns.columns = (
datetime_frame_columns.columns
.map(lambda x: x.strftime('%Y%m%d')))
assert_frame_equal(test, datetime_frame_columns)
# test NaTs
nat_index = to_datetime(
['NaT'] * 10 + ['2000-01-01', '1/1/2000', '1-1-2000'])
nat_frame = DataFrame({'A': nat_index}, index=nat_index)
nat_frame.to_csv(path, date_format='%Y-%m-%d')
test = read_csv(path, parse_dates=[0, 1], index_col=0)
assert_frame_equal(test, nat_frame)
def test_to_csv_with_dst_transitions(self):
with ensure_clean('csv_date_format_with_dst') as path:
# make sure we are not failing on transitions
times = pd.date_range("2013-10-26 23:00", "2013-10-27 01:00",
tz="Europe/London",
freq="H",
ambiguous='infer')
for i in [times, times + pd.Timedelta('10s')]:
time_range = np.array(range(len(i)), dtype='int64')
df = DataFrame({'A': time_range}, index=i)
df.to_csv(path, index=True)
# we have to reconvert the index as we
# don't parse the tz's
result = read_csv(path, index_col=0)
result.index = to_datetime(result.index).tz_localize(
'UTC').tz_convert('Europe/London')
assert_frame_equal(result, df)
# GH11619
idx = pd.date_range('2015-01-01', '2015-12-31',
freq='H', tz='Europe/Paris')
df = DataFrame({'values': 1, 'idx': idx},
index=idx)
with ensure_clean('csv_date_format_with_dst') as path:
df.to_csv(path, index=True)
result = read_csv(path, index_col=0)
result.index = to_datetime(result.index).tz_localize(
'UTC').tz_convert('Europe/Paris')
result['idx'] = to_datetime(result['idx']).astype(
'datetime64[ns, Europe/Paris]')
assert_frame_equal(result, df)
# assert working
df.astype(str)
with ensure_clean('csv_date_format_with_dst') as path:
df.to_pickle(path)
result = pd.read_pickle(path)
assert_frame_equal(result, df)
def test_to_csv_quoting(self):
df = DataFrame({
'c_bool': [True, False],
'c_float': [1.0, 3.2],
'c_int': [42, np.nan],
'c_string': ['a', 'b,c'],
})
expected = """\
,c_bool,c_float,c_int,c_string
0,True,1.0,42.0,a
1,False,3.2,,"b,c"
"""
result = df.to_csv()
assert result == expected
result = df.to_csv(quoting=None)
assert result == expected
result = df.to_csv(quoting=csv.QUOTE_MINIMAL)
assert result == expected
expected = """\
"","c_bool","c_float","c_int","c_string"
"0","True","1.0","42.0","a"
"1","False","3.2","","b,c"
"""
result = df.to_csv(quoting=csv.QUOTE_ALL)
assert result == expected
# see gh-12922, gh-13259: make sure changes to
# the formatters do not break this behaviour
expected = """\
"","c_bool","c_float","c_int","c_string"
0,True,1.0,42.0,"a"
1,False,3.2,"","b,c"
"""
result = df.to_csv(quoting=csv.QUOTE_NONNUMERIC)
assert result == expected
msg = "need to escape, but no escapechar set"
tm.assert_raises_regex(csv.Error, msg, df.to_csv,
quoting=csv.QUOTE_NONE)
tm.assert_raises_regex(csv.Error, msg, df.to_csv,
quoting=csv.QUOTE_NONE,
escapechar=None)
expected = """\
,c_bool,c_float,c_int,c_string
0,True,1.0,42.0,a
1,False,3.2,,b!,c
"""
result = df.to_csv(quoting=csv.QUOTE_NONE,
escapechar='!')
assert result == expected
expected = """\
,c_bool,c_ffloat,c_int,c_string
0,True,1.0,42.0,a
1,False,3.2,,bf,c
"""
result = df.to_csv(quoting=csv.QUOTE_NONE,
escapechar='f')
assert result == expected
# see gh-3503: quoting Windows line terminators
# presents with encoding?
text = 'a,b,c\n1,"test \r\n",3\n'
df = pd.read_csv(StringIO(text))
buf = StringIO()
df.to_csv(buf, encoding='utf-8', index=False)
assert buf.getvalue() == text
# xref gh-7791: make sure the quoting parameter is passed through
# with multi-indexes
df = pd.DataFrame({'a': [1, 2], 'b': [3, 4], 'c': [5, 6]})
df = df.set_index(['a', 'b'])
expected = '"a","b","c"\n"1","3","5"\n"2","4","6"\n'
assert df.to_csv(quoting=csv.QUOTE_ALL) == expected
def test_period_index_date_overflow(self):
# see gh-15982
dates = ["1990-01-01", "2000-01-01", "3005-01-01"]
index = pd.PeriodIndex(dates, freq="D")
df = pd.DataFrame([4, 5, 6], index=index)
result = df.to_csv()
expected = ',0\n1990-01-01,4\n2000-01-01,5\n3005-01-01,6\n'
assert result == expected
date_format = "%m-%d-%Y"
result = df.to_csv(date_format=date_format)
expected = ',0\n01-01-1990,4\n01-01-2000,5\n01-01-3005,6\n'
assert result == expected
# Overflow with pd.NaT
dates = ["1990-01-01", pd.NaT, "3005-01-01"]
index = pd.PeriodIndex(dates, freq="D")
df = pd.DataFrame([4, 5, 6], index=index)
result = df.to_csv()
expected = ',0\n1990-01-01,4\n,5\n3005-01-01,6\n'
assert result == expected
def test_multi_index_header(self):
# see gh-5539
columns = pd.MultiIndex.from_tuples([("a", 1), ("a", 2),
("b", 1), ("b", 2)])
df = pd.DataFrame([[1, 2, 3, 4], [5, 6, 7, 8]])
df.columns = columns
header = ["a", "b", "c", "d"]
result = df.to_csv(header=header)
expected = ",a,b,c,d\n0,1,2,3,4\n1,5,6,7,8\n"
assert result == expected