定义:字符串是一个有序的字符集合,用来存储和表示文本信息。用双引和单引表示。是一种不可变类型。
创建:
In [9]:
s = 'Hello Python'
print(s)
Hello Python
常用操作:
In [1]:
# 索引和切片
s = 'Python'
print(s[1]) # y
print(s[-1]) # n
print(s[1:4]) # yth 顾头不顾尾
y
n
yth
In [2]:
# capitalize() 首字母大写
s = 'hello python'
print(s.capitalize()) # Hello python
Hello python
In [3]:
# upper() lower() 全大写和全小写
s1 = 'hello python'
s2 = 'HELLO PYTHON'
print(s1.upper()) # Hello python
print(s2.lower()) # hello python
HELLO PYTHON
hello python
In [4]:
# title() 每个隔开(特殊字符和数字)的单词的首字母大写
s = 'life is short you need python'
print(s.title()) # Life Is Short You Need Python
Life Is Short You Need Python
In [11]:
# center() 两边按指定字符填充 居中
s = 'python'
print(s.center(20,'-')) # -------python-------
-------python-------
In [10]:
# len() 长度 字符数
s = 'i love you jiang zi ya'
print(len(s)) # 22
s1 = '我喜欢你'
print(len(s1)) # 4
22
4
In [16]:
# startswith(www.quwanyule157.com) 判断是否以什么什么开头 支持指定起始和终止
s = 'jiang ziya'
print(s.startswith('jiang')) # True
print(s.startswith(www.yongshiyule178.com 'ziya')) # False
print(s.startswith('jiang',0,5)) # True
print(s.startswith('jiang'www.taohuayuangw.com,0,4)) # False
True
False
True
False
In [19]:
# find() 查找每个字符的索引 没找到返回-1 支持指定起始和终止
s = 'jiang zi ya'
print(s.find('z'))
print(s.find('zi'))
print(s.find('Jiang'))
6
6
-1
In [20]:
# index() 查找每个字符的索引 没找到报错
print(s.index('z'))
print(s.index('zi'))
# print(s.index('Jiang'))
6
6
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-20-ff6187789150> in <module>
2 print(s.index('z'))
3 print(s.index('zi'))
----> 4print(s.index(www.gcyL157.com'Jiang'))
ValueError: substring not found
In [36]:
# strip() 去除两边的指定字符串 默认删空格 rstrip() 左边 lstrip() 右边
s = ' python '
print(s.strip(www.michenggw.com))
print(s.strip('www.mingcheng178.com/ '))
print(s.strip(' '))
print(''.center(20,'-'))
s1 = '*%jiang*%wei*%%%%'
print(s1.strip('*%'))
python
python
python
--------------------
jiang*%wei
In [46]:
# count() 计算某个字符的个数 支持指定起始和终止位置
s = 'Python python'
print(s.count('t'))
print(s.count('jiang'))
2
0
In [58]:
# split() 按照指定字符切割 默认按照空格切割 返回列表
s = ' i love you '
print(s.split())
print(s.split(' '))
s1 = '--he--he--he--'
print(s1.split('--'))
['i', 'love', 'you']
['', 'i', 'love', 'you', '']
[' i love you ']
['', 'he', 'he', 'he', '']
In [61]:
# replace() 替换 可以指定替换数
s = 'who are you who are you who are you'
print(s.replace('you','she'))
print(s.replace('you','she',2))
who are she who are she who are she
who are she who are she who are you
In [69]:
# is系列
name = 'jiangziya1'
print(name.isalpha()) # 判断字符串是否由字母组成
print(name.isalnum()) # 判断字符串是否由数字和字母组成
print(name.isdigit()) # 判断字符串是否右数字组成
False
True
False
002---Python基本数据类型--字符串
猜你喜欢
转载自my.oschina.net/u/3386278/blog/2980665
今日推荐
周排行