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

執行結果：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)

結果：5

========如何查詢所有‘i’在字串中位置呢？===========

#開掛模式
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)
      

執行結果：

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