Python：有没有一种方法可以查找和删除字符串中字符的第一个和最后一个出现的位置？

Question

The problem:

Given a string in which the letter h occurs at least twice. Remove from that string the first and the last occurrence of the letter h, as well as all the characters between them.

How do I find the first and last occurrence of h? And how can I remove them and the characters in between them?

#initialize the index of the input string
index_count =0

#create a list to have indexes of 'h's
h_indexes = []

#accept input strings
origin_s = input("input:")

#search 'h' and save the index of each 'h' (and save indexes of searched 'h's into h_indexes
for i in origin_s:

first_h_index =
last_h_index = 

#print the output string
print("Output:"+origin_s[     :     ]+origin_s[     :])

Answer 1

You need to use regex:

>>> import re
>>> s = 'jusht exhamplhe'
>>> re.sub(r'h.+h', '', s)
'juse'

Answer 2

Using a combination of index , rindex and slicing :

string = 'abc$def$ghi'
char = '$'
print(string[:string.index(char)] + string[string.rindex(char) + 1:])
# abcghi

Answer 3

How do I find the first and last occurrence of h?

First occurence:

first_h_index=origin_s.find("h");

Last occurence:

last_h_index=origin_s.rfind("h");

And how can I remove them and the characters in between them?

Slicing

Answer 4

string = '1234-123456789'
char_list = []
for i in string:
    char_list.append(string[i])

char_list.remove('character_to_remove')

According to the documentation, remove(arg) is a method acting on a mutable iterable (for example list ) that removes the first instance of arg in the iterable.

Answer 5

This will help you to understand more clearly:

string = 'abchdef$ghi'

first=string.find('h')

last=string.rfind('h')

res=string[:first]+string[last+1:]

print(res)