如何在Python中重复字符串中的单个字符

Question

I know that

"123abc" * 2

evaluates as "123abc123abc" , but is there an easy way to repeat individual letters N times, eg convert "123abc" to "112233aabbcc" or "111222333aaabbbccc" ?

Answer 1

What about:

>>> s = '123abc'
>>> n = 3
>>> ''.join([char*n for char in s])
'111222333aaabbbccc'
>>> 

(changed to a list comp from a generator expression as using a list comp inside join is faster )

Answer 2

An alternative itertools -problem-overcomplicating-style option with repeat() , izip() and chain() :

>>> from itertools import repeat, izip, chain
>>> "".join(chain(*izip(*repeat(s, 2))))
'112233aabbcc'
>>> "".join(chain(*izip(*repeat(s, 3))))
'111222333aaabbbccc'

Or, "I know regexes and I'll use it for everything"-style option:

>>> import re
>>> n = 2
>>> re.sub(".", lambda x: x.group() * n, s)  # or re.sub('(.)', r'\1' * n, s) - thanks Eduardo
'112233aabbcc'

Of course, don't use these solutions in practice.

Answer 3

或者另一种方法是使用map ：

"".join(map(lambda x: x*7, "map"))

Answer 4

If you want to repeat individual letters you can just replace the letter with n letters eg

>>> s = 'abcde'
>>> s.replace('b', 'b'*5, 1)
'abbbbbcde'

Answer 5

Or using regular expressions:

>>> import re
>>> s = '123abc'
>>> n = 3
>>> re.sub('(.)', r'\1' * n, s)
'111222333aaabbbccc'

Answer 6

And since I use numpy for everything, here we go:

import numpy as np
n = 4
''.join(np.array(list(st*n)).reshape(n, -1).T.ravel())

Answer 7

@Bahrom's answer is probably clearer than mine, but just to say that there are many solutions to this problem:

>>> s = '123abc'
>>> n = 3
>>> reduce(lambda s0, c: s0 + c*n, s, "")
'111222333aaabbbccc'

Note that reduce is not a built-in in python 3, and you have to use functools.reduce instead.

Answer 8

Another way:

def letter_repeater(n, string):
    word = ''
    for char in list(string):
        word += char * n
    print word

letter_repeater(4, 'monkeys')


mmmmoooonnnnkkkkeeeeyyyyssss

Answer 9

here is my naive solution

text = "123abc"
result = ''
for letters in text:
    result += letters*3

print(result)

output: 111222333aaabbbccc

Answer 10

Python:

def  LetterRepeater(times,word) :
    word1=''
    for letters in word:
        word1 += letters * times
    print(word1)

    word=input('Write down the word :   ')
    times=int(input('How many times you want to replicate the letters ?    '))
    LetterRepeater(times,word)