python_basics

Example Python program python_basics.py For Python version 2.x. To test your Python version use:

python --version

Classes

• class Dog:

Methods

• def myFunc():
• def myPlus(x, y):
• def init(self, age):
• def printAge(self):

Code

Python example

#!/usr/bin/python

print "Hello"

# If
# Code blocks are differentiated by their indentation
# Complex statements, such as "if" require header line, which ends with colon (:)
if True:
   print "Answer"
   print "True"
else:
   print "Answer"
   print "False"

# This is how to wair for user input
raw_input("\n\nPress the enter key to exit.")

# Variables
x = 10
print x
x = "dsfdsf"
print x

# We can delete object references
del x
# This will throw exception
# print x

# Type conversion
x = 5    # x is int
y = float(5)    # y is float
print y

# Ifs can be one line
if (x == 5) : print "x is 5"

# Functions
def myFunc():
    print "My Function"
    return

myFunc()

def myPlus(x, y):
    return x + y

print myPlus(1, 5)

# Classes
class Dog:
   # This is class variable (like static in Java)
   # This is referenced ad Dog.counter
   counter = 0

   # This is constructor
   def __init__(self, age):
         # Here we access instance variable
      self.age = age

   def printAge(self):
      print self.age

dog = Dog(5)
dog2 = Dog(10)

dog.printAge()    # result is 5
dog2.printAge()    # result is 10

print Dog.counter     # result is 0

Dog.counter = 123
print Dog.counter
print dog.counter
print dog2.counter
# result is all the same 123, because all class instances share the same class variable

Useful Links

• Articles: https://python-commandments.org/
• Python shell: https://bsdnerds.org/learn-python/
• Tutorial: https://pythonprogramminglanguage.com/