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pythonstringlistsplit
Qais Albeaiz
Qais Albeaiz

Reputation: 7

how to split string by multi lengths?

this is my first question in this form.

For example : I have this string === 294216673539910447 And have this list of numbers === [3, 2, 3, 3, 2, 2, 3] I need the output === [294, 21, 667, 353, 99, 10, 447]

All what I found in the form is spliting by x, but nothing about multi x

Upvotes: 0

Views: 283

Answers (5)

Lixin Wei
Lixin Wei

Reputation: 533

Try this:

def split(s, len_arr):
    res = []
    start = 0
    for part_len in len_arr:
        res.append(s[start:start+part_len])
        start += part_len
    return res

> split("294216673539910447", [3, 2, 3, 3, 2, 2, 3])
> ['294', '21', '667', '353', '99', '10', '447']

Upvotes: 2

koro
koro

Reputation: 356

Another approach would be - Converting to String and splitting by index.

In Python, it can be done in the following way,

number = str(294216673539910447)
split = [3, 2, 3, 3, 2, 2, 3]
count = 0
result = []
for s in split:
    result.append(int(number[count:s+count]))
    count += s
print(result)

which gives output:

[294, 21, 667, 353, 99, 10, 447]

Upvotes: 1

wjandrea
wjandrea

Reputation: 32964

I wrote a function that can do this, flexibly and with different kinds of input

import itertools

def splits(sequence, indexes, relative=False):
    """
    Split sequence at each index in "indexes".

    If "relative" is True, each index is taken as relative to the previous one.

    >>> list(splits('hello world', [3, 6]))
    ['hel', 'lo ', 'world']
    >>> list(splits('hello world', [3, 3], relative=True))
    ['hel', 'lo ', 'world']
    """
    if relative:
        indexes = itertools.accumulate(indexes)
    start = None
    for stop in itertools.chain(indexes, [None]):
        yield sequence[start:stop]
        start = stop  # For next loop

In practice:

>>> list(splits('294216673539910447', [3, 2, 3, 3, 2, 2], True))
['294', '21', '667', '353', '99', '10', '447']

Note that you don't need the last index in the input list.

Upvotes: 1

jizhihaoSAMA
jizhihaoSAMA

Reputation: 12672

Use an iterator, and use "".join() to concate them,like:

def split(s, arr):
    iterator = iter(s)
    return ["".join(next(iterator) for _ in range(length)) for length in arr]

print(split('294216673539910447', [3, 2, 3, 3, 2, 2, 3]))

Result:

['294', '21', '667', '353', '99', '10', '447']

Upvotes: 1

mathfux
mathfux

Reputation: 5949

There is no multisplit in Python, so it's a good occasion to implement it yourself.

I know a functional way how I would go using numpy and I'll try to repeat the same steps using Python purely:

from itertools import accumulate
s = '294216673539910447'
numbers = [3, 2, 3, 3, 2, 2, 3]
idx = list(accumulate(numbers, initial=0))
print([s[i:j] for i,j in zip(idx[:-1], idx[1:])])

This illustrates a beautiful way to apply cumulative sums. accumulate calculates index positions and they are [0, 3, 5, 8, 11, 13, 15, 18]. So you need to arrange them properly to get slices 0:3, 3:5, ..., 15:18.

Output 
['294', '21', '667', '353', '99', '10', '447']

Upvotes: 2

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