[SOLVED] Importing Python libraries and gracefully handling if they are not availalble

Importing Python libraries and gracefully handling if they are not availalble

I would like to import bunch of libraries and catch the exception.

If I have only 1 try catch block I get 1 exception (the first one). Is there a pattern to iterate over all of the libs and have a separate exception for each individual missing lib?

#!/usr/bin/env python

try: import sys
except: print sys.exc_info()
try: import numpy as np
except: print sys.exc_info()
try: import scipy as sp
except: print sys.exc_info()
try: import os as os
except: print sys.exc_info()
try: from operator import itemgetter
except: print sys.exc_info()
try: import socket
except: print sys.exc_info()
try: import logging
except: print sys.exc_info()
try: from time import gmtime, strftime
except: print sys.exc_info()

Solution

You can use __import__ to dynamically import modules, allowing you to - among other things - import modules by iterating a list with their names.

For example:

libnames = ['numpy', 'scipy', 'operator']
for libname in libnames:
    try:
        lib = __import__(libname)
    except:
        print(sys.exc_info())
    else:
        globals()[libname] = lib

You can either extend that to handle the import ... as ... and from ... import ... forms or just do the assignments later manually, ie.:

np = numpy
sp = scipy
itemgetter = operator.itemgetter