Simple Python to Check LIbraries -

i found code somewhere checks if there packages installed.

# python program can executed report whether particular # python packages available on system.  import os import math import sys  def test_numpy():     try:         import numpy np     except importerror:         print("could not import numpy -> numpy failed")         return none     # simple test     = np.arange(0, 100, 1)     assert np.sum(a) == sum(a)     print("-> numpy ok")   def test_scipy():     try:         import scipy     except importerror:         print("could not import 'scipy' -> scipy failed")         return none     # simple test     import scipy.integrate     assert abs(scipy.integrate.quad(lambda x: x * x, 0, 6)[0] - 72.0) < 1e-6     print("-> scipy ok")   def test_pylab():     """actually testing matplotlib, pylab part of matplotlib."""     try:         import pylab     except importerror:             print("could not import 'matplotlib/pylab' -> failed")             return none     # creata plot testing purposes     xvalues = [i * 0.1 in range(100)]     yvalues = [math.sin(x) x in xvalues]     pylab.plot(xvalues, yvalues, "-o", label="sin(x)")     pylab.legend()     pylab.xlabel('x')     testfilename='pylab-testfigure.png'      # check file not exist yet:     if os.path.exists(testfilename):         print("skipping plotting file file {} exists already."\             .format(testfilename))     else:         # write plot file         pylab.savefig(testfilename)         # check file exists         assert os.path.exists(testfilename)         print("-> pylab ok")         os.remove(testfilename)   def test_sympy():     try:         import sympy     except importerror:             print("could not import 'sympy' -> fail")             return none     # simple test     x = sympy.symbol('x')     my_f = x ** 2     assert sympy.diff(my_f,x) == 2 * x     print("-> sympy ok")   def test_pytest():     try:         import pytest     except importerror:             print("could not import 'pytest' -> fail")             return none     print("-> pytest ok")   if __name__ == "__main__":     print("running using python {}".format(sys.version))      print("testing numpy...     "),     test_numpy()      print("testing scipy...     "),     test_scipy()      print("testing matplotlib..."),     test_pylab()      print("testing sympy...     "),     test_sympy()      print("testing pytest...    "),     test_pytest() 

i don't understand why there tests ?

without tests can assert libraries there no exceptions thrown, right ?

can remove tests , expect correct results regarding package installations ?

like:

def test_numpy():         try:             import numpy np         except importerror:             print("could not import numpy -> numpy failed")             return none        

also, test supposed work in every kind of python distribution anaconda etc ?

does depend upon version of python using?

thanks lot help.