# 单行注释
print('''hello_world''')  # 单行注释
''' 
多行注释
多行注释
多行注释
多行注释
'''
print("=================================")
# 算数运算符 + - * /
# // 取整除
a = 9 // 2
print(a)
# % 取余
b = 9 % 2
print(b)
# ** 幂运算
c = 9 ** 2
print(c)
print("=================================")
first_name = 'mist'
last_name = 'ray'
name = first_name + last_name
print(name)

# 条件控制
print("=================================")
i = 1
if i == 1:
    print("1111")
else:
    print("2222")
# 流程控制
print("=================================")
for z in range(5):
    print(z)

print("=================================")
zzz = 0
while zzz < 5:
    zzz = zzz + 1
    print(zzz)
