I want to check whether a library is installed and can be imported dynamically at runtime within an if statement to handle it properly.

I've tried the following code:

try:
    import foo
    print("Foo installed")
except ImportError:
    print("Foo not installed")

It works as intended but does not seem like the most elegant method.

I was thinking more of a method that returns a boolean indicating whether the library is installed, something like:

Class.installed("foo")  # returns a boolean

I want to check whether a library is installed and can be imported dynamically at runtime within an if statement to handle it properly.

I've tried the following code:

try:
    import foo
    print("Foo installed")
except ImportError:
    print("Foo not installed")

It works as intended but does not seem like the most elegant method.

I was thinking more of a method that returns a boolean indicating whether the library is installed, something like:

Class.installed("foo")  # returns a boolean

• python
• python-3.x

• 6 Nope, try/except is the accepted and usual method. – Tim Roberts Commented Mar 10 at 21:58
• This question is similar to: Check if module exists, if not install it. If you believe it’s different, please edit the question, make it clear how it’s different and/or how the answers on that question are not helpful for your problem. – JonSG Commented Mar 11 at 14:11

2 Answers 2

Use importlib.util for a clean check.

import importlib.util

if importlib.util.find_spec("library_name") is not None:  
    print("Installed")

This code defines a function that checks if a package is installed:

def is_installed(pkg):
    try:
        __import__(pkg)
        return True
    except ImportError:
        return False

if is_installed("foo"):
    print("Foo installed")
else:
    print("Foo not installed")

It uses __import__, which allows to pass the name of the module to be imported as a string.