python script in cron not reading a CSV unless it creates the CSV itself

问题

I have the following script. It works when I run it in command line, and it works when I run it in cron.

The variable 'apath' is the absolute path of the file.

cat=['a','a','a','a','a','b','b','b','b','b']
val=[1,2,3,4,5,6,7,8,9,10]
columns=['cat','val']
data=[cat,val]
dict={key:value for key,value in zip(columns,data)}

statedata_raw=pd.DataFrame(data=dict)
statedata_raw.to_csv(apath+'state_data.csv',index=False)

statedata_raw2=pd.read_csv(apath+'state_data.csv')
statedata_raw2.to_csv(apath+'state_data2.csv',index=False)

But when I try to run the first part manually, creating the first csv, and then run the second part through cron, the second read_csv statement fails. I checked the permissions on the state_data.csv file and they are fine. It's set to -rwxr-xr-x

To be specific: I first run this script manually through command line. It executes and creates state_data.csv. Then I check the permissions of state_csv, and they are -rwxr-xr-x

cat=['a','a','a','a','a','b','b','b','b','b']
val=[1,2,3,4,5,6,7,8,9,10]
columns=['cat','val']
data=[cat,val]
dict={key:value for key,value in zip(columns,data)}

statedata_raw=pd.DataFrame(data=dict)
statedata_raw.to_csv(apath+'state_data.csv',index=False)

and then this script via cron, which fails, and gives the error message below

statedata_raw2=pd.read_csv(apath+'state_data.csv')
statedata_raw2.to_csv(apath+'state_data2.csv',index=False)

This is the error that I get from the system

Traceback (most recent call last):
  File "/users/michaelmader/wdtest.py", line 39, in <module>
    statedata_raw2=pd.read_csv(apath+'state_data.csv')
  File "/opt/miniconda3/lib/python3.7/site-packages/pandas/io/parsers.py", line 676, in parser_f
    return _read(filepath_or_buffer, kwds)
  File "/opt/miniconda3/lib/python3.7/site-packages/pandas/io/parsers.py", line 448, in _read
    parser = TextFileReader(fp_or_buf, **kwds)
  File "/opt/miniconda3/lib/python3.7/site-packages/pandas/io/parsers.py", line 880, in __init__
    self._make_engine(self.engine)
  File "/opt/miniconda3/lib/python3.7/site-packages/pandas/io/parsers.py", line 1114, in _make_engine
    self._engine = CParserWrapper(self.f, **self.options)
  File "/opt/miniconda3/lib/python3.7/site-packages/pandas/io/parsers.py", line 1891, in __init__
    self._reader = parsers.TextReader(src, **kwds)
  File "pandas/_libs/parsers.pyx", line 374, in pandas._libs.parsers.TextReader.__cinit__
  File "pandas/_libs/parsers.pyx", line 678, in pandas._libs.parsers.TextReader._setup_parser_source
OSError: Initializing from file failed

To summarize

Run complete script through Terminal: state_data2.csv is created: pass
Run complete script through cron: state_data2.csv is created: pass
Run first part through Terminal, second part through cron: fail

I am on MacOS and I already gave crontab full disk access in system preferences.

回答1:

I figured out the problem. The issue was the permissions that were granted to cron in MacOS. I thought I had solved it by giving \usr\bin\crontab full disk access, but I actually needed to give full disk access to usr\sbin\cron

The steps for doing this can be found here: https://blog.bejarano.io/fixing-cron-jobs-in-mojave/.

Once I made that change everything worked fine.

来源：https://stackoverflow.com/questions/62353610/python-script-in-cron-not-reading-a-csv-unless-it-creates-the-csv-itself

标签

python-3.x

csv

permissions

cron