CODEWITHSUNDEEP
pythonstringlistpython-2.7
Vincent A
Vincent A

Reputation: 77

Convert and modify list in python

I have a list like so obtained after some mathematic operations:

[[899, 6237], [898, 6237], [897, 6237],
 [896, 6237], [895, 6237], [899, 6238],
 [898, 6238], [897, 6238], [896, 6238],
 [895, 6238], [899, 6239], [898, 6239],
 [897, 6239], [896, 6239], [895, 6239],
 [899, 6240], [898, 6240], [897, 6240],
 [896, 6240], [895, 6240]]

I would like the components of each sublist become string of 4 characters size. This is a example of what I want with the first element of the main list:

['0899','6237']

Upvotes: -1

Views: 52

Answers (4)

Joe T. Boka
Joe T. Boka

Reputation: 6589

You can use a simple list comprehension

new_list = [['0' + str(i[0]), str(i[1])]  for i in original_list]

new_list output:

[['0899', '6237'], ['0898', '6237'], ['0897', '6237'], ['0896', '6237'], ['0895', '6237'], ['0899', '6238'], ['0898', '6238'], ['0897', '6238'], ['0896', '6238'], ['0895', '6238'], ['0899', '6239'], ['0898', '6239'], ['0897', '6239'], ['0896', '6239'], ['0895', '6239'], ['0899', '6240'], ['0898', '6240'], ['0897', '6240'], ['0896', '6240'], ['0895', '6240']]

Upvotes: 1

J.J
J.J

Reputation: 3607

The correct way is to use format(), although the zfill is also pretty sweet. Here is a much uglier solution that no one should ever use:

list = [
 [899, 6237], [898, 6237], [897, 6237], [896, 6237], [895, 6237], [899, 6238],
 [898, 6238], [897, 6238], [896, 6238], [895, 6238], [899, 6239], [898, 6239],
 [897, 6239], [896, 6239], [895, 6239], [899, 6240], [898, 6240], [897, 6240],
 [896, 6240], [895, 6240]
]

def yolo(pair):
    pair = map(str,pair)
    return ['0'*(4-len(pair[0])) + pair[0], pair[1]]

list = map(yolo,list)

Upvotes: 1

Ahasanul Haque
Ahasanul Haque

Reputation: 11134

You can use zfill with list comprehension:

list_name = [[str(i).zfill(4) for i in element] for element in your_list]

Demo:

>>>str(890).zfill(4)
'0890'
>>>str(890).zfill(5)
'00890'

Upvotes: 1

falsetru
falsetru

Reputation: 368964

Using list comprehension and format:

>>> lst = [
...     [899, 6237], [898, 6237], [897, 6237], [896, 6237], [895, 6237],
...     [899, 6238], [898, 6238], [897, 6238], [896, 6238], [895, 6238],
...     [899, 6239], [898, 6239], [897, 6239], [896, 6239], [895, 6239],
...     [899, 6240], [898, 6240], [897, 6240], [896, 6240], [895, 6240],
... ]
>>> [[format(a, '04'), format(b, '04')] for a, b in lst]
[['0899', '6237'], ['0898', '6237'], ['0897', '6237'], ['0896', '6237'],
 ['0895', '6237'], ['0899', '6238'], ['0898', '6238'], ['0897', '6238'],
 ['0896', '6238'], ['0895', '6238'], ['0899', '6239'], ['0898', '6239'],
 ['0897', '6239'], ['0896', '6239'], ['0895', '6239'], ['0899', '6240'],
 ['0898', '6240'], ['0897', '6240'], ['0896', '6240'], ['0895', '6240']]

You can also use str.format:

>>> '{:04}'.format(899)
'0899'

or %-operator (printf-style formatting):

>>> '%04d' % 899
'0899'

Upvotes: 2

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