python中怎么返回指定查找字符的位置

发布网友发布时间：2022-04-24 17:52

共5个回答

懂视网时间：2022-04-18 18:26

下面为大家分享一篇Python 查找字符在字符串中的位置实例，具有很好的参考价值，希望对大家有所帮助。一起过来看看吧

str_1='wo shi yi zhi da da niu '
char_1='i'
nPos=str_1.index(char_1)
print(nPos)

运行结果：7

========是使用find==========

str_1='wo shi yi zhi da da niu '
char_1='i'
nPos=str_1.find(char_1)
print(nPos)

结果：5

========如何查找所有‘i'在字符串中位置呢？===========

#开挂模式
str_1='wo shi yi zhi da da niu '
char_1=str(input('Please input the Char you want:'))
count=0
str_list=list(str_1)
for each_char in str_list:
 count+=1
 if each_char==char_1:
 print(each_char,count-1)

运行结果：

Please input the Char you want:i
i 0
i 1
i 2
i 3

热心网友时间：2022-04-18 15:34

Python编程中对字符串进行搜索查找，并返回字符位置，案例代码如下：

# multiple searches of a string for a substring
# using s.find(sub[ ,start[, end]])
#以下面test这段文本为例
text = 'MSKSASPKEPEQLRKLFIGGLSFETTDESLRSAHFESSSYGSAGRRF'
##查找上面文本中的SA字符串
search = 'SA'
start = 0
while  True:
    index = text.find(search, start)
    # if search string not found, find() returns -1
    # search is complete, break out of the while loop
    if index == -1:
        break
    print( "%s found at index %d"  % (search, index) )
    # move to next possible start position
    start = index  + 1
//运行结果：
#SA found at index 3
#SA found at index 31
#SA found at index 41

热心网友时间：2022-04-18 16:52

用re吧

>>> import re
>>> word = "test"
>>> s = "test abcd test 1234 testcase testsuite"
>>> [m.start() for m in re.finditer(word, s)]
[0, 10, 20, 29]

热心网友时间：2022-04-18 18:27

>>> def find_pos(str, tobefind):
...     L = len(tobefind)
...     def xiter():
...         for i, c in enumerate(str):
...             if c==tobefind[0] and str[i:i+L] == tobefind:
...                 yield i
...     return list(xiter())
...
>>> find_pos('test test tst testa testb', 'test')
[0, 5, 14, 20]
>>>

热心网友时间：2022-04-18 20:18

#常规循环版
def findn(cs,ms,n=1):
    finalLoc=0
    matchLen=len(ms)
    for i in range(n):
        midLoc=cs.index(ms)
        cs=cs[(midLoc+matchLen):]
        if i==0:
            finalLoc+=midLoc
        else:
            finalLoc+=midLoc+matchLen
    return finalLoc

#递归版
def findn(cs,ms,n=1,loc=0):
    if n==1:
        return loc+cs.index(ms)
    else:
        start=cs.index(ms)+len(ms)
        return findn(cs[start:],ms,n-1,start+loc)

print findn('abaabbbbbab','a',3)

#生成器版
def findn(cs,ms,loc=0):
    nloc=cs.find(ms)
    if nloc!=-1:
        start=nloc+len(ms)
        yield nloc+loc
        for i in findn(cs[start:],ms,start+loc):
            yield i
print list(findn('aaaababbbabab','ab'))

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python中怎么返回指定查找字符的位置