• list copy
• reverse list
• cast format (str -> int)
• zip two lists
• list mathematical

list copy

inspired by How to clone or copy a list? in stackoverflow

clone_list = sample_list.copy()

# or
clone_list = sample_list[:]

# or
clone_list = list(sample_list)

# or
import copy
clone_list = copy.copy(sample_list)

# or
import copy
clone_list = copy.deepcopy(sample_list)

# or
>>> id(x)
4505979072
>>> k = x
>>> id(k)
4505979072

>>> k = x.copy()
>>> id(k)
4445208000
>>> k = x[:]
>>> id(k)
4505977632
>>> import copy
>>> k = copy.copy(x)
>>> id(k)
4505754352
>>> k = copy.deepcopy(x)
>>> id(k)
4505978352
>>> k = x[:]
>>> id(k)
4506260896
>>> k = copy.deepcopy(x)
>>> id(k)
4506261136

reverse list

sample_list[::-1]

# example
>>> ['1', '2', '3', '4', '5'][::-1]
['5', '4', '3', '2', '1']

cast format (str -> int)

list( map(int, sample_list) )

# example
>>> print( list( map(int, ['2', '8', '4', '127', 'HKD'][:3][::-1] ) ) )
[4, 8, 2]

zip two lists

>> from itertools import zip_longest
>>> x = ['1', '2', '3', '4']
>>> y = ['one', 'two', 'three', 'four']
>>> for i, j in zip_longest( x, y ):
  print(i, j)

1 one
2 two
3 three
4 four

# or zip to a map
>>> x = ['1', '2', '3', '4']
>>> y = ['one', 'two', 'three', 'four']
>>> print( {key: value for key, value in zip_longest(x, y)} )
{'1': 'one', '2': 'two', '3': 'three', '4': 'four'}

list mathematical

# sum
>>> n = ['1', '2', '3', '4']
>>> print( sum( list( map(int, n) ) ) )
10

# multiplication