python day2 字符串的方法

1、首字母大写

name = "wuyuchao"
result = name.capitalize()
print(result)

返回 Wuyuchao

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2、内容居中

name = "wuyuchao"
result = name.center(20,'*') #20代表长度，*代表填充字符
print(result)

返回 ******wuyuchao******

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3、子序列个数

name = "wuyuchao"
result = name.count('yu')
print(result) 
返回 1 yu出现了1次
result2 = name.count('nnn')
print(result2)
返回 0 nnn没有出现

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4、编码

name = "吴玉超"
result = name.encode("gbk")
print(result)

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5、大小写转换

name = "wuyuchao"
result = name.swapcase()
print(result)
返回 WUYUCHAO

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6、是否以***结束

name = "wuyuchao"
result1 = name.endswith("o")
result2 = name.endswith("x")
print(result1,result2)
返回 True False

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7、是否以***开始

name.startswith()

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8、子序列出现的次数

name = "wwuuyyuucchhaaoo"
result = name.count('u')
print(result)
返回 4，字符串中出现了4次u

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9、将tab替换为8个空格

name = "w\tuyuchao"
print(name)    返回 w uyuchao
result = name.expandtabs()
print(result)  返回 w       uyuchao

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10、查询子序列在字符串中的位置，如果没有，返回-1

name = "wuyuchao"
result = name.find("w")
result2 = name.find("h")
result3 = name.find("x")
print(result,result2,result3)

返回 w 0 ,h 5 ,x -1  字符串中不包含x 返回-1

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11、查询子序列在字符串中的位置，如果没有，直接报错

name = "wuyuchao"
result = name.index("w")
result2 = name.index("h")
返回 w 0 ,h 5
result3 = name.index("x")
直接报错

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12、字符串格式化

name = "wu{0}{1}" #数字从0开始
result = name.format("yu","chao")
print(result)
返回 wuyuchao

name = "wu{ming}{zi}"
result = name.format(ming="yu",zi="chao")
print(result)
返回 wuyuchao

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13、是否是字母和数字

name = "wuyuchao123"
print(name.isalnum())

返回True

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14、是否是字母

name = "FABacasd"
print(name.isalpha()) 返回True
name2 = "FABacasd1"
print(name2.isalpha()) 返回False

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15、是否是数字

name = "1"
print(name.isdigit())

True

name = "a"
print(name.isdigit())

False

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16、是否为小写

name.islower()

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17、是否为大写

name.isupper()

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18、字符串连接

li = ['w','u','y','u','c','h','a','o']
result = "".join(li)
print(result)

返回 wuyuchao

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19、内容右对齐

name = "wuyuchao"
result = name.rjust(20)
print(result)

返回             wuyuchao

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20、转换为小写

name = "WUYUCHAO"
result = name.swapcase()
print(result)

返回 wuyuchao

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21、移除右侧空白

name = "wuyuchao "
print(name)
result = name.rstrip()
print(result)

name 右侧有空格
result 右侧没有了空格

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22、分割，前、中、后三部分

name = "wuyuchao"
result = name.partition("yu")
result2 = name.partition("wu")
print(result,result2)

返回 ('wu', 'yu', 'chao') ('', 'wu', 'yuchao')

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23、替换

name = "wuyuchao"
result = name.replace("yu","YU")
print(result)

返回 wuYUchao

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