How to save python screen output to a text file

Question

I'd like to query items from a dict and save the printed output to a text file.

Here's what I have:

import json
import exec.fullog as e

inp = e.getdata() #inp now is a dict() which has items, keys and values.

#Query

print('Data collected on:', inp['header']['timestamp'].date())
print('\n CLASS 1 INFO\n')

for item in inp['Demographics']:
    if item['name'] in ['Carly', 'Jane']:
        print(item['name'], 'Height:', item['ht'], 'Age:', item['years'])

for item in inp['Activity']:
    if item['name'] in ['Cycle', 'Run', 'Swim']:
        print(item['name'], 'Athlete:', item['athl_name'], 'Age:', item['years'])

Answer 1

Let me summarize all the answers and add some more.

• To write to a file from within your script, user file I/O tools that are provided by Python (this is the f=open('file.txt', 'w') stuff.

• If don't want to modify your program, you can use stream redirection (both on windows and on Unix-like systems). This is the python myscript > output.txt stuff.

• If you want to see the output both on your screen and in a log file, and if you are on Unix, and you don't want to modify your program, you may use the tee command (windows version also exists, but I have never used it)

• Even better way to send the desired output to screen, file, e-mail, twitter, whatever is to use the logging module. The learning curve here is the steepest among all the options, but in the long run it will pay for itself.

Answer 2

A quick and dirty hack to do this within the script is to direct the screen output to a file:

import sys 

stdoutOrigin=sys.stdout 
sys.stdout = open("log.txt", "w")

and then reverting back to outputting to screen at the end of your code:

sys.stdout.close()
sys.stdout=stdoutOrigin

This should work for a simple code, but for a complex code there are other more formal ways of doing it such as using Python logging.