在python中拆分乱序字符串

我不确定我是否完全理解您的问题。在我看来，您好像想要输入：

XABCDE

或者，等效地（至少就我在您的符号中可以看出）：

BCXADE
DEBCXA

并返回一个像

{"x": "A","b": "C","d": "E"}

（这是表示名称-值对的一种方式）。

这样对吗？如果是这样：

# This is the input.
c = "XABCDE"

# This is a Dictionary comprehension,one way
# of creaTing a set of key-value pairs.
{
    c[idx].lower(): c[idx + 1]      # Map the first element of each pair to the second.
    for idx in range(0,len(C),2)  # Iterate over the pairs in the String. 
}

自从我最初的回答以来，这个问题已经进行了实质性的编辑，所以我要添加一个单独的答案。

OP 的输入如下：有一个文件 foo.txt，内容如下：

Header A
blab
iuyt
Header B
bkas
rtyu
Header C
asdf

OP 的预期输出是将标题 values 映射到标题后面的内容（不是行）的字典，即：

{
    "A": "blab\niuyt","B": "bkas\nrtyu","C": "asdf"
}

注意每个新标题之前的最后一个尾随行分隔符 (\n) 不应被包含在内。

一种方法：

import re

from collections import defaultDict

# Given something like "Header A" with a Trailing newline,# this will match "A" under group "key". The header formats
# in the example are simple enough that you could fetch the
# value using _,group = line.split(" "),but this accomodates
# more complex formats. Note that this regular expression 
# assumes each header will be followed by at leasT ONE line
# of data in a file!
PATTERN = re.compile(r"^Header\s*(?P<key>.+)(\r\n|\r|\n)")

# Using defaultDict with an str constructor means we don't have to check 
# for key existence before attempTing an append. check the standard library
# documentation for more info:
# https://docs.python.org/3/library/collections.html#collections.defaultDict
structured_output = defaultDict(str)

with open("txt","r") as handle:
    last_match = None  # Track the second-last match we made.

    for line in handle:
        maybe_match = PATTERN.match(linE)

        if maybe_match:  # We've matched a new header group. Strip the Trailing newline from preceding,if any.
            # This is either (a) the FIRST header we're matching or (b) the n-th header.
            # In the first case,structured_output[key] returns "" (see defaultDict),and "".rStrip("\n")
            # is "". In the second case,we Strip the last newline from the previous group (per the speC).
            group = (last_match or maybe_match).group("key")
            structured_output[group] = structured_output[group].rStrip()

            # Move the last_match "pointer" forWARD to the 
            # new header.
            last_match = maybe_match

        else:  # This is not a header,it's a line of data: append it.
            structured_output[last_match.group("key")] += line

    # Once we've run off the end of the file,we should still rStrip the _last_ group.
    structured_output[last_match.group("key")] = structured_output[last_match.group("key")].rStrip()

使用迭代器：

it = iter(String1)
res = {C: next(it) for c in it}