Learning Python

Learning basic of python like data type, list, dictionary, function, class, turtle, interface.

Note:

Python is a case-sensitive language which is heavily rely on indentation or spacing.

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Examples

Comments

# This is a one-line Python comment - code blocks are so useful!
"""This type of comment is used to document the purpose of functions and classes."""

Declaration/Initialization

# Remember values, not variables, have data types.
# A variable can be reassigned to contain a different data type.
answer = 42
answer = "The answer is 42."

Data Types

boolean = True
number = 1.1
string = "Strings can be declared with single or double quotes."
list = ["Lists can have", 1, 2, 3, 4, "or more types together!"]
tuple = ("Tuples", "can have", "more than", 2, "elements!")
dictionary = {'one': 1, 'two': 2, 'three': 3}
variable_with_zero_data = None

NOTE:

Both lists and tuples are sequence data types that can store a collection of items.
Difference:
lists ---> mutable whereas
tuple ---> immutable.
A mutable data type means that a python object of this type can be modified.

Simple Logging

print "Printed!"

Conditionals

cake = "okay"
if cake == "delicious":
    print("Yes please!")   
elif cake == "okay":
    print("I'll have a small piece.")   
else:
    print("No, thank you.")

Loops

for item in list:
    print item

while (total < max_val):
    total += values[i]
    i += 2

Range

There are three ways you can call range() :

• range(stop) takes one argument.
• range(start, stop) takes two arguments.
• range(start, stop, step) takes three arguments.

for i in range(2, 10, 2):
    print(i)
print('Goodbye!')

Functions

def divide(dividend, divisor):
    quotient = dividend / divisor
    remainder = dividend % divisor
    return quotient, remainder

def calculate_stuff(x, y):
    (q, r) = divide(x,y)
    print q, r

Classes

class Person(object):
    def __init__(self, name, age):
        self.name = name
        self.age = age 

    def birthday(self):
        self.age += 1