Python

= Basics=

Variables
Declaring Variables: list=[1,2,3] string="Hello" int=23

Basic argument specifiers:

%s                     - String (or any object with a string representation, like numbers) %d                     - Integers %f                     - Floating point numbers %. f  - Floating point numbers with a fixed amount of digits to the right of the dot. %x/%X                  - Integers in hex representation (lowercase/uppercase)

Indentation is Mandatory in python:

num=12 if num>5: print("Number is greater than 5") if num<20: print("Number is lesser than 20") print("Program Ended")

Operator Precedence from highest to lowest order:



Statements
IF & ELIF statements:

num=9 if num==5: print("Number is 5") elif num ==11: print("Number is 11") elif num==7: print("Number is 7") else: print("Number isn't 5,11,7")

AND returns true only if both are true >>> 1 == 1 and 2==2 True >>> 1 == 1 and 2==3 False >>> 1 != 1 and 2==2 False >>> 1 == 1 and 2==2 True

OR returns true if either of both arguments are true; false if both are false. >>> 1 != 1 or 2==2 True >>> 1 == 1 or 2==2 True >>> 1 == 1 or 2==3 True

Lists
words=["Hello","World","!"] print(words[0]) print(words[1]) print(words[2])

Mixed List: number=3 things=['string',0,[1,2,number],4,56] print(things[1]) print(things[2]) print(things[2][2])

List Operators: nums = [1,2,3] print(nums+[4,5,6]) print(nums*3)

in operator: >>> words=['spam',"egg"] >>> print("spam" in words) True >>> print("tomato" in words) False >>> print (not "tomato" in words) True >>> print ("tomato" not in words) True

Append to the list: nums=[1,2,3] nums.append(4) print(nums)

Len function:

nums=[1,3,5,2,4] print(len(nums))
 * 1) Unlike append, len is a normal function rather than a method.
 * 2) Therefore it is written before the list it is being called on, without a dot.

Insert Method is similar to append, but allows to add at any position in the list words=["Python","fun"] index=1 words.insert(index,"is") print(words)

Loops
While Loop runs more than once, till condition is true, once condition is false, next section of code is executed: i=1 while i<=500: print(i) i=i+1

print("Finished !")

Infinity while loop: condition always remain True: while 1==1: print('In a loop..!!')

Break the infinity Loop: i=0 while 1==1: print(i) i=i+1 if i>=25: print('Breaking!') break

print("Finished!")

Continue this jumps back to top of the loop, rather than stopping it i=0 while True: i=i+1 if i==10: print('Skip 10') continue if i==25: print("Breaking") break print(i) print("Finished!")

words = ["hello","world","spam","egg"] counter = 0 max_index = len(words)-1
 * While Loop

while counter <= max_index: word = words[counter] print(word + "!") counter = counter + 1

words = ["hello","world","spam","egg"] for word in words: print(word + "!")
 * Same code can be created using FOR Loop but fewer lines

= GUI =

Hello World
from Tkinter import Tk, Label

root = Tk

w = Label(root, text="Hello World!") w.pack

root.mainloop