另一种方法是使用列表(假设你正在寻找的子字符串是由数字组成的，只是):

string = 'gfgfdAAA1234ZZZuijjk'
numbersList = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
output = []

for char in string:
    if char in numbersList: output.append(char)

print(f"output: {''.join(output)}")
### output: 1234

你可以在你的代码中找到这个函数的第一个子字符串(通过字符索引)。此外，还可以找到子字符串后面的内容。

def FindSubString(strText, strSubString, Offset=None):
    try:
        Start = strText.find(strSubString)
        if Start == -1:
            return -1 # Not Found
        else:
            if Offset == None:
                Result = strText[Start+len(strSubString):]
            elif Offset == 0:
                return Start
            else:
                AfterSubString = Start+len(strSubString)
                Result = strText[AfterSubString:AfterSubString + int(Offset)]
            return Result
    except:
        return -1

# Example:

Text = "Thanks for contributing an answer to Stack Overflow!"
subText = "to"

print("Start of first substring in a text:")
start = FindSubString(Text, subText, 0)
print(start); print("")

print("Exact substring in a text:")
print(Text[start:start+len(subText)]); print("")

print("What is after substring \"%s\"?" %(subText))
print(FindSubString(Text, subText))

# Your answer:

Text = "gfgfdAAA1234ZZZuijjk"
subText1 = "AAA"
subText2 = "ZZZ"

AfterText1 = FindSubString(Text, subText1, 0) + len(subText1)
BeforText2 = FindSubString(Text, subText2, 0) 

print("\nYour answer:\n%s" %(Text[AfterText1:BeforText2]))

在python中，可以使用正则表达式(re)模块中的findall方法从字符串中提取子字符串。

>>> import re
>>> s = 'gfgfdAAA1234ZZZuijjk'
>>> ss = re.findall('AAA(.+)ZZZ', s)
>>> print ss
['1234']

打印稿。获取两个字符串之间的字符串。

搜索前缀和后缀之间的最短字符串

前缀-字符串/字符串数组/ null(意味着从开始搜索)。

Postfixes -字符串/字符串数组/ null(意味着搜索直到结束)。

public getStringInBetween(str: string, prefixes: string | string[] | null,
                          postfixes: string | string[] | null): string {

    if (typeof prefixes === 'string') {
        prefixes = [prefixes];
    }

    if (typeof postfixes === 'string') {
        postfixes = [postfixes];
    }

    if (!str || str.length < 1) {
        throw new Error(str + ' should contain ' + prefixes);
    }

    let start = prefixes === null ? { pos: 0, sub: '' } : this.indexOf(str, prefixes);
    const end = postfixes === null ? { pos: str.length, sub: '' } : this.indexOf(str, postfixes, start.pos + start.sub.length);

    let value = str.substring(start.pos + start.sub.length, end.pos);
    if (!value || value.length < 1) {
        throw new Error(str + ' should contain string in between ' + prefixes + ' and ' + postfixes);
    }

    while (true) {
        try {
            start = this.indexOf(value, prefixes);
        } catch (e) {
            break;
        }
        value = value.substring(start.pos + start.sub.length);
        if (!value || value.length < 1) {
            throw new Error(str + ' should contain string in between ' + prefixes + ' and ' + postfixes);
        }
    }

    return value;
}

使用sed，可以对字符串执行如下操作:

echo "$STRING" | sed -e "s|.*AAA\(.*\)ZZZ.*|\1|"

结果是1234。

你可以使用相同的正则表达式对re.sub函数做同样的事情。

>>> re.sub(r'.*AAA(.*)ZZZ.*', r'\1', 'gfgfdAAA1234ZZZuijjk')
'1234'

在基本sed中，捕获组由\(..\)表示，但在python中由(..)表示。

此外，您可以在波纹函数中找到所有的组合

s = 'Part 1. Part 2. Part 3 then more text'
def find_all_places(text,word):
    word_places = []
    i=0
    while True:
        word_place = text.find(word,i)
        i+=len(word)+word_place
        if i>=len(text):
            break
        if word_place<0:
            break
        word_places.append(word_place)
    return word_places
def find_all_combination(text,start,end):
    start_places = find_all_places(text,start)
    end_places = find_all_places(text,end)
    combination_list = []
    for start_place in start_places:
        for end_place in end_places:
            print(start_place)
            print(end_place)
            if start_place>=end_place:
                continue
            combination_list.append(text[start_place:end_place])
    return combination_list
find_all_combination(s,"Part","Part")

结果:

['Part 1. ', 'Part 1. Part 2. ', 'Part 2. ']