前言
今天我们说了字符串的基础,格式化,这次我们讲解字符串的常用函数,不要错过!
前两篇都在本文同个专栏,欢迎关注。下面开始讲解。
字符串都有哪些操作?
实际开发都有这些需求:
第一大类:判断识别字符串
- 判断字符串属于那种字面类型(数字,全字母,其他)
- 判断字符串包含某些结构(数字大写,局部子串,子串出现频次等)
第二类:字符串编辑的操作(生成新字符串)
- 字符串的替换/合并/填充等
- 字典替换,填充0值,清空操作等
第三类:字符串跟字节串的互转。
这类操作通常发生在数据跨程序/跨服务器传输,我们传输bytes,然后获取转string类型。
第一类 判断识别字符串
学委准备了下面的代码:
#!/usr/bin/env python # -*- coding: utf-8 -*- # @Time : 2021/10/30 10:13 上午 # @Author : LeiXueWei # @CSDN/Juejin/Wechat: 雷学委 # @XueWeiTag: CodingDemo # @File : string_funs_cat1.py # @Project : hello import sys slogan = "keep studying, keep coding, I am Levin" # 判断结构 print("算某个子串出现数次: slogan.count('keep') = ", slogan.count('keep')) print("找某个子串首次出现的下标: slogan.find('keep') = ", slogan.find('keep')) print("找某个子串最后出现的下标: slogan.rfind('keep') = ", slogan.rfind('keep')) print("找某个子串下标: slogan.index('keep') = ", slogan.index('keep')) print("找某个子串下标: slogan.rindex('keep') = ", slogan.rindex('keep')) print("是否'keep'开头的字符串: slogan.startswith('keep') = ", slogan.startswith('keep')) print("是否'keep'结束的字符串: slogan.endswith('keep') = ", slogan.endswith('keep')) # 字符串属性相关 pr<i style="color:transparent">本文来源gaodai$ma#com搞$代*码6网</i>int("字符串长度: len(slogan) = ", len(slogan)) print("字符串是否都是空格: slogan.isspace() = ", slogan.isspace()) print("字符串是否大写: slogan.isupper() = ", slogan.isupper()) print("字符串是否小写: slogan.islower() = ", slogan.islower()) print("字符串是否为每个词首字母都大写: slogan.istitle() = ", slogan.istitle()) # 判断字符串数据类型 print("字符串是否全为字母: slogan.isalpha() = ", slogan.isalpha()) print("字符串是否全为数字: slogan.isalnum() = ", slogan.isalnum()) print("字符串是否数字: slogan.isnumeric() = ", slogan.isnumeric()) print("字符串是否浮点数: slogan.isdecimal() = ", slogan.isdecimal()) print("字符串是否为空格串: slogan.isspace() = ", slogan.isspace())
读者可以直接复制运行代码,学委补充了运行效果图: