Issue with compression in to_csv method

[nvm1]

Problem description

Hi there,

after upgrading to the lastest version of pandas I have an issue with the code, that worked fine on the previous version (0.22.0):

            df.to_csv(
                path_or_buf=csv_path,
                encoding='utf8',
                compression='gz',
                quoting=1,
                sep='\t',
                index=False)

With pandas 0.23.0 I get:

Traceback (most recent call last):
File "C:_script.py", line 74, in
index=False)
File "C:\Anaconda3\lib\site-packages\pandas\core\frame.py", line 1745, in to_csv
formatter.save()
File "C:\Anaconda3\lib\site-packages\pandas\io\formats\csvs.py", line 158, in save
data = f.read()
File "C:\Anaconda3\lib\encodings\cp1252.py", line 23, in decode
return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x90 in position 298: character maps to

If I comment compression='gz' the code works fine.

Output of pd.show_versions()

INSTALLED VERSIONS

commit: None
python: 3.6.5.final.0
python-bits: 64
OS: Windows
OS-release: 2012ServerR2
machine: AMD64
processor: Intel64 Family 6 Model 63 Stepping 2, GenuineIntel
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8
LOCALE: None.None

pandas: 0.23.0
pytest: 3.5.1
pip: 10.0.1
setuptools: 39.1.0
Cython: 0.28.2
numpy: 1.14.3
scipy: 1.1.0
pyarrow: None
xarray: None
IPython: 6.4.0
sphinx: 1.7.4
patsy: 0.5.0
dateutil: 2.7.3
pytz: 2018.4
blosc: None
bottleneck: 1.2.1
tables: 3.4.3
numexpr: 2.6.5
feather: None
matplotlib: 2.2.2
openpyxl: 2.5.3
xlrd: 1.1.0
xlwt: 1.3.0
xlsxwriter: 1.0.4
lxml: 4.2.1
bs4: 4.6.0
html5lib: 1.0.1
sqlalchemy: 1.2.7
pymysql: None
psycopg2: 2.7.4 (dt dec pq3 ext lo64)
jinja2: 2.10
s3fs: None
fastparquet: None
pandas_gbq: None
pandas_datareader: None

[jreback]

you would have to show a reproducible example

[ghost]

My apologies if I'm missing something, but shouldn't the compression value for GNU zip be, 'gzip', rather than 'gz'? https://pandas.pydata.org/pandas-docs/version/0.23/generated/pandas.DataFrame.to_csv.html

[nvm1]

Thank you for the responses.

Well, I can't reproduce the issue with pandas 0.23.0 on my home machine, but it appears on two of my windows servers at work. I will try to make a clean install of anaconda on one of them and see what happens.

yeah, @CamWhitelaw, you're absolutely right. I've actually tried to change my code before pasted it here, in original version of my code it uses gzip.

[minggli]

Please let us know if re-install anaconda solved the issue.

[minggli]

did some digging, it might be different default encoding which open() falls to when not specified. then on windows it tried to decode with CP1252 when your file is UTF-8 encoded.

[nvm1]

Hi there,

Sorry for being slow. I did a clean installation of anaconda and still I get the same error.

It works fine on my home machine, but fails on both servers.

[WillAyd]

@nvm1 this should be fixed on master via the referenced PR