在 Python 中，流程控制语句用于控制程序的执行流程。常见的流程控制语句包括条件语句（如 if 语句）和循环语句（如 for 和 while 语句）。本文将介绍这些基本的流程控制语句，并提供一些示例代码。
1 条件判断 #
if (2 <= 3) and (7 != 8):
print((2 <= 3) and (7 != 8)) # True
if not (1 == 1):
print(not (1 == 1))
else:
print(not (1 == 1)) # False
score = int(input("Enter score:\n"))
if score > 100 or score < 0:
print('Invalid score. Please enter a score between 0 and 100.')
elif score >= 90:
print('Grade: A')
elif score >= 80:
print('Grade: B')
elif score >= 70:
print('Grade: C')
elif score >= 60:
print('Grade: D')
else:
print('Grade: F')2 随机数 #
import random
RR = random.randint(1, 100)
II = input('Please enter a number between 0 and 100.\n')
II = int(II)
if II < RR:
print('Too low!')
elif II > RR:
print('Too high!')
else:
print('Correct!')3 while 循环 #
i = 1
while i <= 5:
j = 1
while j <= i: # 嵌套
print("*", end=" ") # 指定打印结束后添加的内容
j += 1
print() # 缩进换行
i += 14 for 循环 #
name = "Hello"
for i in name:
print(i, end=" ") # H e l l o
print()
for i in range(1, 6):
for j in range(1, i + 1):
print("*", end=" ")
print()5 break 和 continue #
在嵌套循环中，break continue 只对当前循环有效，不会影响外层循环。
for i in range(1, 11):
if i == 5:
break
print(i, end=" ")
print()
for i in range(1, 11):
if i == 5:
continue
print(i, end=" ")
print()