1.if条件表达式判断
##判断条件是true or false
var1=10
if var1:
print("true")
print(var1)
else:
print("false")
print(var1)
var2=0
if var2:
print("true")
print(var2)
else:
print("false")
print(var2)
输出结果：
true
10
false
0
2. 判断输入的字符是否一致
SIZE="hello"
char=input("输入字符名称:")
if char == SIZE:
print("字符名称%s"%char,"等于",SIZE)
else:
print("请输入字符",SIZE)
输出结果：
输入字符名称:hello
字符名称hello 等于 hello
--------------------------
输入字符名称:world
请输入字符 hello
3.判断登录验证用户名密码
user="desperado
pwd="" username=input("用户名：")
password=input("密码：") if username == user and password == pwd:
print("login successful ...")
elif username != user:
print("the user does not exist")
else:
print("login fail")