Python硬币翻转程序while循环问题：随机结果始终单一

作为Python初学者，我写的硬币翻转程序有问题：random函数没达到预期效果。我希望计算机每次随机选head或tail，但运行结果要么全是head要么全是tail。以下是我的代码和运行结果，该怎么修改？

原代码 #

print("\n\tWelcome to the 'Flip a coin' program")

import random

input("\nPress the enter key to start playing!")

flip_coin=random.randint(1,2)

heads=0
tails=0
rolls=int(input("\nPlease, tell the computer how many rolls you want to do? "))
essai=0

while essai<rolls:
    essai+=1
    if flip_coin==1:
        heads+=1
        print("You've got a head")
    else:
        tails+=1
        print("You've got a tail")

print("\n\tThe job is done..")
print("\n\tYou have a total of", heads,"heads and", tails,"tails")

运行结果 #

Welcome to the 'Flip a coin' program

Press the enter key to start playing!

Please, tell the computer how many rolls you want to do? 10
You've got a head
You've got a head
You've got a head
You've got a head
You've got a head
You've got a head
You've got a head
You've got a head
You've got a head
You've got a head

    The job is done..

    You have a total of 10 heads and 0 tails

问题根源 #

你只在循环外生成了一次随机数flip_coin=random.randint(1,2)，之后循环里每次判断都用这个固定值，自然每次结果都一样。

修改方法 #

把生成随机数的代码移到while循环内部，让每次循环都重新生成一个1或2的随机数，这样每次翻转才会随机。

修改后的完整代码 #

print("\n\tWelcome to the 'Flip a coin' program")

import random

input("\nPress the enter key to start playing!")

heads=0
tails=0
rolls=int(input("\nPlease, tell the computer how many rolls you want to do? "))
essai=0

while essai<rolls:
    essai+=1
    # 每次循环重新生成随机数
    flip_coin=random.randint(1,2)
    if flip_coin==1:
        heads+=1
        print("You've got a head")
    else:
        tails+=1
        print("You've got a tail")

print("\n\tThe job is done..")
print("\n\tYou have a total of", heads,"heads and", tails,"tails")

额外优化建议 #

可以用random.choice(['head', 'tail'])直接生成结果，代码更直观：

# 替换原判断部分
result = random.choice(['head', 'tail'])
if result == 'head':
    heads +=1
    print("You've got a head")
else:
    tails +=1
    print("You've got a tail")

内容的提问来源于stack exchange，提问作者A_heath