CODEWITHSUNDEEP
pythonpython-3.xpip
Mikhail_Sam
Mikhail_Sam

Reputation: 11218

Using `pip freeze > requirements` in Python code

I found how to use pip command in code:

import subprocess
subprocess.call(["pip", "freeze"])

It displays all packages in command prompt.

But it doesn't work this way:

import subprocess
subprocess.call(["pip", "freeze", ">", "requirements.txt"])

It doesn't writes it to file, it prints in console again.

How to run this command in the right way?

Upvotes: 1

Views: 2722

Answers (2)

Alex Hall
Alex Hall

Reputation: 36033

Redirection is implemented in the shell/terminal, that means the command must be executed in the shell using shell=True keyword argument. Otherwise subprocess executes the first item in the list and uses the rest as arguments to it. See the documentation for subprocess for more information.

subprocess.call("pip freeze > requirements.txt", shell=True)

Upvotes: 5

han solo
han solo

Reputation: 6590

Use this:

>>> with open('requirements.txt', 'w') as file_:
...   subprocess.Popen(['pip', 'freeze'], stdout=file_).communicate()
...

or, call if you prefer that

>>> with open('requirements.txt', 'w') as file_:
    ...   subprocess.call(['pip', 'freeze'], stdout=file_)

Upvotes: 7

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