去掉字符串中的 space 字符

string_var = "  \t a string example\n\t\r  "
print(string_var)
string_var = string_var.lstrip()  # trim white space from left
print(string_var)
string_var = "  \t a string example\t  "
string_var = string_var.rstrip()  # trim white space from right
print(string_var)
string_var = "  \t a string example\t  "
string_var = string_var.strip()  # trim white space from both side
print(string_var)

Output:

       a string example
a string example
       a string example
a string example