与find()方法不同的是,index()方法在找不到子字符串时会抛出ValueError异常,因此需要进行异常处理。 deffind_all_positions(string,substring):positions=[]start=0try:whileTrue:position=string.index(substring,start)positions.append(position)start=position+1exceptValueError:passreturnpositions string="Hello, Worl...
PythonUserPythonUser输入字符串和子字符串调用 find() 方法返回子字符串位置 接下来,我们还可以用甘特图来表示整个查找过程的时间线,以便更直观地理解执行过程。 甘特图 2023-01-022023-01-022023-01-022023-01-032023-01-032023-01-04User inputs string and substringPython calls find()Python returns positionSt...
Note that find() function returns the index position of the substring if it’s found, otherwise it returns -1. count() functionto find the number of occurrences of a substring in the string. s = 'My Name is Pankaj' print('Substring count =', s.count('a')) s = 'This Is The Bes...
#defining string and substring str1 = "This dress looks good; you have good taste in clothes."...
The index method can’t return a number because the substring isn’t there, so we get a value error instead: In order to avoid thisTraceback Error, we can use the keywordinto check if a substring is contained in a string. In the case of Loops, it was used for iteration, whereas in...
Python 字符串直接在方括号([])中使用索引即可获取对应的字符,其基本语法格式为:string[index] 这里的 string 表示要截取的字符串,index 表示索引值。 【例1】s = 'crazyit.org is very good' # 获取s中索引2处的字符 print(s[2]) # 输出a
print(quote.find('o small ',10,-1)) # Substring is searched in 'll things with'print(quote.find('things ',6,20)) Run Code Output -1 3 -1 9 Also Read: Python String index() Python String count()
string='All around the world' substring =string[4:10] print(substring) # Print "around" 使用负索引对字符串进行切片 如果你不知道这个字符串的长度,你想获取最后一个字符改如何处理呢?方法一,是先获取字符串长度,然后取最后一个值:string[len(string) - 1]方法二,是使用负索引:string[-1]很明显,使用...
.format(name, age)) # 使用f-string格式化 print(f"{name} is {age} years old.") 2.1.3 切片与索引操作 Python字符串支持切片操作,类似于列表,可以通过索引来访问和截取子字符串: string = "Python Programming" substring = string[7:14] # 从索引7开始至索引14前结束 print(substring) # 输出:"...
ValueError: substring not found >>> str.index("n") #同find类似,返回第一次匹配的索引值 4 >>> str.rindex("n") #返回最后一次匹配的索引值 11 >>> str.count('a') #字符串中匹配的次数 0 >>> str.count('n') #同上 2 >>> str.replace('EAR','ear') #匹配替换 'string learn' >...