if / elif / else

if x > 0:
    pass
elif x == 0:
    pass
else:
    pass

for 循环

for i in range(n):          # 0 .. n-1
    pass

for i in range(1, n + 1):   # 1 .. n
    pass

for i, x in enumerate(a):   # 带下标
    pass

for x in lst:               # 遍历元素
    pass

while

while n > 0:
    n //= 2

break / continue / else

for 带 else：未 break 时执行（不常用）。

列表推导式

squares = [x * x for x in range(10)]
evens = [x for x in a if x % 2 == 0]

多组数据

import sys
data = sys.stdin.read().split()
it = iter(data)
# 或逐行 while True: line = input(); if not line: break