Python assert Keyword
Example
Test if a condition returns True:
    x = "hello"
#if condition returns True, then nothing happens:
assert x == "hello"
#if condition returns 
    False, AssertionError is raised:
assert x == "goodbye"
  Run example »
Definition and Usage
The assert keyword is used when debugging 
code.
The assert keyword lets you test if a 
condition in your code returns True, if not, the program will raise an 
AssertionError.
You can write a message to be written if the code returns False, check the example below.
More Examples
Example
Write a message if the condition is False:
    x = "hello"
#if condition returns 
    False, AssertionError is raised:
assert x == "goodbye", "x 
    should be 'hello'"
  Run example »

