__1. Datatypes in Python:__

- None
- Numeric
- float -> 1.5
- int -> 5
- complex -> 2+5j
- bool -> True/false
- Sequence
- List -> [3,5,6,7,1]
- Tuple -> (3,5,6,7,1)
- Set -> {3,5,6,7,1}
- String -> "Akshay"
- Range
- range(5) -> range(0, 5)
- list(range(5)) -> [0,1,2,3,4]
- list(range(2,10,2)) -> [2,4,6,8]
- Dictonary
- product_price = {'book': 50, 'pen': 300, 'eraser': 10}
- product_price.get('book') -> 50

__2. Number Conversion in Python__**bin(**28**)**->**0b**11100**oct(**28**)**->**0o**34**hex(**28**)**->**0x**1c

__3. Swap two numbers in Python__**a = 5**

**b = 6**

**Method #1:**

**a, b = b, a**

**Method #2**

**a = a + b**

**b = a - b**

**a = a - b**

__4. "math" module in python__

**import math**

- math.sqrt(25) -> 5.0
- math.floor(2.5) -> 2.0
- math.ceil(2.5) -> 3.0
- math.pow(2, 3) -> 8.0
- math.pi -> 3.141592653589793
- math.e -> 2.718281828459045

__5. How to import a module in python__- import math
- import math as m
- from math import sqrt, pow

__6. How to take input from command line in python__

from sys import argv

x = int(argv[1])

y = int(argv[2])

z = x + y

print(z)

__7. Print below pattern in Python__str1 = "ABCD"

str2 = "PQR"

for i in range(4):

print(str1[:i+1]+str2[i:])

__8. Use else with for loop in python__- for loop must have 'break' statement in it to use the 'else'.
- example: find the number in the list that is divisible by 2

digits = [7, 3, 5, 11]

for digit in digits:

if digit%2==0:

print(digit)

break;

else:

print('not found!')

__9. Array in python__- Array is similar to list but must have elements of same datatype.

from array import *

# 'i' denotes the type of array i.e. integer

digits = array('i', [1,2,4,5,7])

# u denotes the unicode type array

unico = array('u', ["a","k","s","h","a","y"])

#copying array

digitcp = array(digits.typecode, [ a for a in digits])

#print array with for loop

for d in unico:

print(d)

*** These notes only meant to remind the basics of Python. These are not full notes.**

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