Python字符串大小写转换拼接删除空白

str = "hello world!"
print(str.title())
Hello World!
print(str.upper())
HELLO WORLD!
print(str.lower())
hello world!

str1 = 'Hello'
str2 = 'World'
print(str1+str2)
HelloWorld
str3 = str1+str2
print(str3)
HelloWorld

string.lstrip() #删除串首的空白
string.rstrip() #删除串尾的空白
string.strip() #删除左右量表的空白

str = ' Hello Beijing '
print(str.lstrip())
print(str.rstrip())
print(str.strip())

Hello Beijing 
 Hello Beijing
Hello Beijing