substring：要查找的子字符串。start（可选）：开始查找的起始位置，默认为 0。end（可选）：结束查找的位置，默认为字符串的长度。示例：1. 查找子字符串：text = "Hello, world! This is an example."# 使用 find 查找子字符串index = text.find("world")print("Index of 'world':", index) # 输出...
Index within range 0 to 10:", index_range) # 输出: Index within range 0 to 10: 7 # 查找不存在的子串 nonexistent_substring = "Python" index_not_found = text.find(nonexistent_substring) print("Index of nonexistent substring:", index_not_found) # 输出: Index of nonexistent substring:...
substring = "world" index = text.find(substring) if index != -1: print(f"Substring found at index {index}.") else: print("Substring not found.") 在这个例子中,find() 方法会在 text 字符串中查找 substring,并返回其索引位置。如果找到了子字符串,它会打印出索引位置;如果没有找到,...
If the substring exists inside the string, it returns the index of the first occurence of the substring. If a substring doesn't exist inside the string, it returns-1. Working of find() method Working of Python string's find() and rfind() methods Example 1: find() With No start and ...
uppercasea_upper = a.upper()print(a_upper) # Output: 'HELLO ACCOUNTANT'# Use the find function to find the index of a substring in the stringindex = a.find('accoun')print(index) # Output: 6# Use the count function to count the number of occurrences of a substring ...
Python String find() The find() method returns the lowest index of the substring if it is found in given string. If its is not found then it returns -1. Syntax : str.find(sub,start,end) Parameters : sub :It’s the substring which needs to be searched in the given string....
**示例**: ```python main_string = "Hello, world!" substring = "world" index = main_string.find(substring) print("The substring '{}' is found at index {}".format(substring, index)) # 输出: The substring 'world' is found at index 7 ``` ### 在 C++ 中使用 `std::find` C++ ...
2. 使用Python进行反向搜索 在字符串中进行反向搜索 在Python中,字符串可以使用切片和rfind()方法来进行反向搜索。rfind()方法返回最后一次出现指定子字符串的索引。如果找不到该子字符串,返回值为-1。 # 在字符串中反向搜索子字符串 substring = "Python" reverse_index = my_string.rfind(substring) # 输出查...
quote="The secret of getting ahead is getting started."ifquote.find('getting')!=-1:print("The substring 'getting' was found in the quote.")else:print("The substring 'getting' was not found in the quote.") 在这个代码示例中,我们检查 'getting' 这个单词是否作为子串出现在了引用中。
find(...) methodofbuiltins.str instance S.find(sub[, start[,end]]) -> intReturnthe lowest indexinSwheresubstringsubisfound, such thatsubiscontained within S[start:end].Optionalarguments startandendare interpretedasinslice notation.Return-1onfailure....