week3--day2 函数

Posted 2020-10-12 躬行致远

# 写函数的时候最好以功能为导向.

# return的两个功能: 1) 返回一个值. 2) 终止当前函数.

# def a():
#     return 1,2,3

# a = a()
# print(a)
# >>>(1, 2, 3)   # 元祖
# a,b,c = a()    # 必须一样.
# print(a,b,c)
# >>>1 2 3

# a,b = {‘name‘:‘a‘, ‘name2‘:‘b‘}
# print(a,b)
# >>>name name2

# ------------- else 用的很有意思 -------------------
# def find_prime_number(number):
#     for i in range(2, number+1):
#         for j in range(2, i):
#             if i % j == 0:
#                 print(i, ‘equals‘, j, ‘*‘, i//j)
#                 break
#         else:
#             print(i, ‘is prime number‘)
# find_prime_number(100)


# f = open(‘010‘, ‘r‘)
# f.truncate(10)    # 截取10个字节

--------------- 函数迭代问题 ----------------------

# 猴和桃子问题.
# 猴子每天吃一半桃子,再扔一个.连续几天后,第六天还有1个,问第一天几个

first_day = 0

def count_peach(arg, days):
    global first_day
    if days == 1:
        first_day = arg
    else:
        days -= 1
        arg += 1
        arg *= 2
        count_peach(arg, days)

count_peach(1, 6)
print(first_day)

>>> 94   # 结果