检查pip是否安装？

Question

I am using Python 2.7.12 and I want to check whether the pip is installed or not. For this, in command line of Python application I wrote pip list and pressed enter. However, I get an error like:

File"stdin",line 1

pip list

Syntax Error: invalid syntax

So, how can I solve this issue and get the list of modules as an output?

Thanks

Answer 1

Use command line and not python.
TLDR; On Windows, do:
python -m pip --version
OR
py -m pip --version

Details:

On Windows, ~> (open windows terminal)
Start (or Windows Key) > type "cmd" Press Enter
You should see a screen that looks like this
To check to see if pip is installed.

python -m pip --version

if pip is installed, go ahead and use it. for example:

Z:\>python -m pip install selenium

if not installed, install pip, and you may need to
add its path to the environment variables . (basic - windows)
add path to environment variables (basic+advanced)

if python is NOT installed you will get a result similar to the one below

Install python. add its path to environment variables.

UPDATE: for newer versions of python replace "python" with py - see @gimmegimme's comment and link https://packaging.python.org/guides/installing-using-pip-and-virtual-environments/

Answer 2

$ which pip

or

 $ pip -V 

execute this command into your terminal. It should display the location of executable file eg. /usr/local/bin/pip and the second command will display the version if the pip is installed correctly.

Answer 3

If you are on a linux machine running Python 2 you can run this commands:

1st make sure python 2 is installed:

python2 --version

2nd check to see if pip is installed:

pip --version

If you are running Python 3 you can run this command:

1st make sure python 3 is installed:

python3 --version

2nd check to see if pip3 is installed:

pip3 --version

If you do not have pip installed you can run these commands to install pip (it is recommended you install pip for Python 2 and Python 3):

Install pip for Python 2:

sudo apt install python-pip

Then verify if it is installed correctly:

pip --version

Install pip for Python 3:

sudo apt install python3-pip

Then verify if it is installed correctly:

pip3 --version

For more info see: https://itsfoss.com/install-pip-ubuntu/

UPDATE I would like to mention a few things. When working with Django I learned that my Linux install requires me to use python 2.7, so switching my default python version for the python and pip command alias's to python 3 with alias python=python3 is not recommended. Therefore I use the python3 and pip3 commands when installing software like Django 3.0, which works better with Python 3. And I keep their alias's pointed towards whatever Python 3 version I want like so alias python3=python3.8 .

Keep In Mind When you are going to use your package in the future you will want to use the pip or pip3 command depending on which one you used to initially install the package. So for example if I wanted to change my change my Django package version I would use the pip3 command and not pip like so, pip3 install Django==3.0.11 .

Notice When running checking the packages version for python: $ python -m django --version and python3: $ python3 -m django --version , two different versions of django will show because I installed django v3.0.11 with pip3 and django v1.11.29 with pip .

Answer 4

pip list is a shell command. You should run it in your shell (bash/cmd), rather than invoke it from python interpreter.

pip does not provide a stable API. The only supported way of calling it is via subprocess , see docs and the code at the end of this answer.

However, if you want to just check if pip exists locally, without running it, and you are running Linux, I would suggest that you use bash's which command:

which pip

It should show you whether the command can be found in bash's PATH /aliases, and if it does, what does it actually execute.

If running pip is not an issue, you could just do:

python -m pip --version

If you really need to do it from a python script, you can always put the import statement into a try...except block:

try:
    import pip
except ImportError:
    print("Pip not present.")

Or check what's the output of a pip --version using subprocess module:

subprocess.check_call([sys.executable, '-m', 'pip', '--version'])

Answer 5

You need to run pip list in bash not in python.

pip list
DEPRECATION: Python 2.6 is no longer supported by the Python core team, please upgrade your Python. A future version of pip will drop support for Python 2.6
argparse (1.4.0)
Beaker (1.3.1)
cas (0.15)
cups (1.0)
cupshelpers (1.0)
decorator (3.0.1)
distribute (0.6.10)
---and other modules

Answer 6

In CMD, type:

pip freeze

And it will show you a list of all the modules installed including the version number.

Output:

aiohttp==1.1.4
async-timeout==1.1.0
cx-Freeze==4.3.4
Django==1.9.2
django-allauth==0.24.1
django-cors-headers==1.2.2
django-crispy-forms==1.6.0
django-robots==2.0
djangorestframework==3.3.2
easygui==0.98.0
future==0.16.0
httpie==0.9.6
matplotlib==1.5.3
multidict==2.1.2
numpy==1.11.2
oauthlib==1.0.3
pandas==0.19.1
pefile==2016.3.28
pygame==1.9.2b1
Pygments==2.1.3
PyInstaller==3.2
pyparsing==2.1.10
pypiwin32==219
PyQt5==5.7
pytz==2016.7
requests==2.9.1
requests-oauthlib==0.6
six==1.10.0
sympy==1.0
virtualenv==15.0.3
xlrd==1.0.0
yarl==0.7.0