Some famous Python one liner code

  Hi Guys !!! Hope all is well

I am going to list down some famous Python one liner code example.

1. Swap two variables

a = 1; b = 2

a, b = b, a

print(a,b) #>> 2 1

2. Multiple variable assignment

Here you can use it to assign list elements to the given variables, which is also called unpacking. The * will do packing the remaining values again, which results in a sublist for c.

a, b, *c = [1,2,3,4,5]

print(a,b,c) #>> 1 2 [3, 4, 5]

3. Sum over every second element of a list

a = [1,2,3,4,5,6]

s = sum(a[1::2])

print(s) #>> 12

4. Delete multiple elements

slicing syntax can also be used to delete multiple list elements at once

a = [1,2,3,4,5]

del a[::2]

print(a) #>> [2, 4]

5. Read file into array of lines

c = [line.strip() for line in open('file.txt')]

print(c) #>> ['sks1', 'sks2', 'sks3', 'sks4']

6. Write string to file

with open('file.txt', 'a') as f: f.write('hello world')

print(list(open('file.txt'))) #['sks1\n', 'sks2\n', 'sks3\n', 'sks4\n', 'hello world!']

7. List creation

# List creation 
list_1 = [('Hi '+ y) for y in ['sks', 'mks','pks']]
print(list_1) #>> ['Hi sks', 'Hi mks', 'Hi pks']

8. List mapping

l = list(map(int, ['1', '2', '3']))
print(l) #>> [1, 2, 3]

You can also use Pythons map() function to cast every list element to another type.

9. Set creation

squares = { x**2 for x in range(6) if x < 4 }
print(squares) #>> {0, 1, 4, 9}

10. Palindrome check

phrase = 'deleveled'
isPalindrome = phrase == phrase[::-1]
print(isPalindrome) #>> true

11. Sum of Even Numbers In a List

a = [1,2,3,4,5,6]

s = sum([num for num in a if num%2 == 0])

print(s)

12. Creating Lists

lst = [i for i in range(0,10)]

print(lst) #[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

# or 

lst = list(range(0,10))

print(lst)

13. Mapping Lists or TypeCasting Whole List

print(list(map(int,['1','2','3']))) #[1, 2, 3]

print(list(map(float,[1,2,3]))) # [1.0, 2.0, 3.0]

print([float(i) for i in [1,2,3]] )# [1.0, 2.0, 3.0]

13. Printing Patterns

n = 5

print('\n'.join('😀' * i for i in range(1, n + 1)))

14. Prime Number

print(list(filter(lambda x:all(x % y != 0 for y in range(2, x)), range(2, 13))))

15. Find Max Number

findmax = lambda x,y: x if x > y else y 

print(findmax(5,14))

Thanks

Saurabh 

Happy Coding !!!