CODEWITHSUNDEEP
pythonpython-2.7
user2182857
user2182857

Reputation: 728

Writing to a text file does not occur in real-time. How to fix this

I have a python script that takes a long time to run.

I placed print-outs throughout the script to observe its progress. As this script different programs, some of whom print many messages, it is unfeasible to print directly to the screen.

Therefore, I am using a report file

f_report = open(os.path.join("//shared_directory/projects/work_area/", 'report.txt'), 'w')

To which I print my massages:

 f_report.write(" "+current_image+"\n")

However, when I look at the file while the script is running, I do not see the messages. They appear only when the program finishes and closes the file, making my approach useless for monitoring on-going progress. What should I do in order to make python output the messages to the report file in real time?

Many thanks.

Upvotes: 3

Views: 4480

Answers (2)

xudesheng
xudesheng

Reputation: 1102

try this:

newbuffer = 0
f_report = open(os.path.join("//shared_directory/projects/work_area/", 'report.txt'), 'w', newbuffer)

it sets up a 0 buffer which will push OS to write content to file "immediately". well, different OS may behavior differently but in general content will be flushed out right away.

Upvotes: 2

Václav Struhár
Václav Struhár

Reputation: 1769

You should use flush() function to write immediately to the file.

f_report.write(" "+current_image+"\n")    
f_report.flush()

Upvotes: 6

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