接上次补充：
s = "username\temail\tpassword\naaa\taa@qq.com\t123\nusername\temail\tpassword\naaa\taa@qq.com\t123"
a = s.expandtabs(20) #断句，以20为单位，不够就自动补齐20个
print(a)
运算结果：
username email password
aaa aa@qq.com 123
username email password
aaa aa@qq.com 123Process finished with exit code 0
其他功能：
1.
#判断当前输入是否为数字
test = '②'
a1 = test.isdecimal() #仅支持数字
a2 = test.isdigit() #支持特殊符号和数字
a3 = test.isnumeric() #支持所有包括中文
print(a1,a2,a3)
运算结果：
False True TrueProcess finished with exit code 0
2.
test = 'sjalfaj\tafaaf'
a1 = test.isprintable() # 是否存在不可显示的字符
print(a1)
运算结果：
FalseProcess finished with exit code 0
test = 'sjalfajafaaf'
a1 = test.isprintable() # 是否存在不可显示的字符
print(a1)
运算结果：
TrueProcess finished with exit code 0
3.判断字符串里是否全是空格
test = 'sjalfa jafaaf'
a1 = test.isspace() # 是否全是空格
print(a1)
运算结果：
FalseProcess finished with exit code 0
4.判断是否是标题（首字母大写）
test = 'sjalfa jafaaf'
a1 = test.istitle()
print(a1)
运算结果：
FalseProcess finished with exit code 0
5.变成标题
test = 'sjalfa jafaaf'
a1 = test.istitle()
a2 = test.title()
print(a1)
print(a2)
运算结果：
False
Sjalfa JafaafProcess finished with exit code 0
6.
#将字符串中的每一个元素按照指定分隔符进行拼接
test = '你好啊猪头'
print(test)
t = ' '
a = t.join(test) #或者 把t.join(test)改成' '.join(test)
print(a)
运算结果：
你好啊猪头
你 好 啊 猪 头Process finished with exit code 0
7.填充
test = 'abcd'
a = test.ljust(20,'*')
a1 = test.center(20,'中')
print(a)
print(a1)
运算结果：
abcd****************
中中中中中中中中abcd中中中中中中中中Process finished with exit code 0
8.只用00填充
test = 'abcd'
a = test.zfill(20)print(a)
运算结果：
0000000000000000abcdProcess finished with exit code 0
9.
test = 'ABCD'
a = test.islower() # 判断是否为小写
a1 = test.lower() # 全部变成小写print(a,a1)
运算结果：
False abcdProcess finished with exit code 0
10.
test = 'abcd'
a = test.isupper() # 判断是否为大写
a1 = test.upper() #变成大写print(a,a1)
运算结果：
False ABCDProcess finished with exit code 0
11.去掉空白（换行\n，空格\t也能去掉）
test = ' abcd '
a = test.lstrip() # 去掉左边空白
#a1 = test.rstrip() #去掉右边空白
#a2 = test.strip() # 去掉全部空白
print(a)
12.移除指定字符串
test = 'abcd'
a = test.lstrip("a")print(a)
运算结果：
bcdProcess finished with exit code 0
13.分割
test = 'lovesdcvvf'
a = test.partition('v') #只能将整个字符串分割成3份
a1 = test.rpartition('v') #从右开始分割成3份
a2 =test.split("v",2) #全部分割
a3 = test.rsplit() #从右开始全部分割
print(a)
print(a1)
print(a2)
print(a3)
运算结果：
('lo', 'v', 'esdcvvf')
('lovesdcv', 'v', 'f')
['lo', 'esdc', 'vf']
['lovesdcvvf']Process finished with exit code 0
14.
test = 'adfsdf\nsafafsad\ndsaf'
a = test.splitlines(True) # 只能根据换行分割， 布尔值用来是否显示换行符
print(a)
运算结果：
['adfsdf\n', 'safafsad\n', 'dsaf']Process finished with exit code 0
15.
test = 'adfsdf\nsafafsad\ndsaf'
a = test.startswith('a') #判断是否以a开头的
b = test.endswith("a") #判断是否以a结尾
print(a)
print(b)
运算结果：
True
FalseProcess finished with exit code 0
16.大小写转换
test = 'abc'
a = test.swapcase()
print(a)
运算结果：
ABCProcess finished with exit code 0
