pip upgrade all

import pkg_resources
from subprocess import call

packages = [dist.project_name for dist in pkg_resources.working_set]
call("pip install --upgrade " + ' '.join(packages), shell=True)

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pip install -U $(pip freeze | awk '{split($0, a, "=="); print a[1]}')

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pip freeze > pip_frozen.txt
pip install -r pip_frozen.txt --upgrade