python中非空即真,非0即真
True: "1" [1] {k-v}
False: None [] {}
username = input("username:").strip()
if username:
print("username不为空")
else:
print("username为空")
python中非空即真,非0即真
True: "1" [1] {k-v}
False: None [] {}
username = input("username:").strip()
if username:
print("username不为空")
else:
print("username为空")