Python 函數的高階操作

Python 函數的高階操作

from functools import reduce
"""
    示例
"""
name = ["joe", "susan", "black", "lili"]
age = [18, 19, 20, 21]
sex = ["m", "w", "m", "w"]

# map 映射函數
# 格式化用戶的英文名，首字母大寫
new_name = map(lambda x:x.title(), name)
new_name = list(new_name)
print(new_name)

# 姓名 年齡 性別 組成元組
users = map(lambda x, y, z:(x, y, z), name, age, sex)
users = list(users)
print(users)

# filter 過濾
# 過濾性別爲男的用戶
new_users = filter(lambda x: x[2]=="m", users)
new_users = list(new_users)
print(new_users)

# reduce 降維
# 求性別爲男性的 年齡的平均數
total_age = reduce(lambda x, y: x+y[1], new_users, 0)
age_avg = total_age / len(new_users)
print(age_avg)