how can i redirect my error message from console to file in Python [duplicate]

Question

I need to redirect my error message from the console to a file. For this example, I need to insert the error message into a file:

Traceback (most recent call last):
  File "C:/Users/", line 5, in <module>
    1/0
ZeroDivisionError: division by zero"

I have already tried to do something like this:

from contextlib import redirect_stdout

with open('error.txt', 'w') as f:
    with redirect_stdout(f):
        1/0
        print('here is my error')

Answer 1

If you plan to run your script in console itself, you can just use the bash's ">" operator to send the input of your command (in this situation : your script) in a file just like this :

python ./yourScript > ./outputFile

Everything that your script will print will go in the specified file.

Answer 2

You need to catch the error or your application will fail:

from contextlib import redirect_stdout

with open('error.txt', 'w') as f:
    try:
        1/0
    except ZeroDivisionError as e:
        f.write(e)

Answer 3

Note: This assumes you're using Bash. I see that you are using Windows, so it's likely that you aren't using Bash. But from what I've read, this should still be applicable if you are using Cmd.exe, it's just that the syntax might be slightly different.

I think it's better to handle error message output outside of your script. Your script should attempt to do the "happy path" work and print an error to stderr if something goes wrong. This is what should happen by default in every programming language. Python gets this right.

Here is an example script:

print("Dividing by 0 now, I sure hope this works!")

1/0

print("Holy cow, it worked!")

If I run this script, the first line prints to stdout, and then the ZeroDivisionError output prints to stderr:

$ python /tmp/script.py 
Dividing by 0 now, I sure hope this works!
Traceback (most recent call last):
  File "/tmp/script.py", line 3, in <module>
    1/0
ZeroDivisionError: integer division or modulo by zero

If I want to run the script and collect any error output in a file, I can use redirection in my shell when I run the command:

$ python /tmp/script.py 2> /tmp/errors.txt
Dividing by 0 now, I sure hope this works!

$ cat /tmp/errors.txt 
Traceback (most recent call last):
  File "/tmp/script.py", line 3, in <module>
    1/0
ZeroDivisionError: integer division or modulo by zero