# Filename : test.py

# author by : www.dida100.com

# 用户输入数字

num = float(input("输入一个数字: "))

if num > 0:

   print("正数")

elif num == 0:

   print("零")

else:

   print("负数")

# Filename ：test.py

# author by : www.dida100.com

# 内嵌 if 语句

num = float(input("输入一个数字: "))

if num >= 0:

   if num == 0:

       print("零")

   else:

       print("正数")

else:

   print("负数")