函数与字典，可选参数和while语句结合的简单应用

python函数可以与各种语句相结合，以达到提高效率简化流程的目的：

1. 通过函数创建字典
   eg. 将歌手与专辑对应，并储存在字典当中

def make_ablum(name, album):
    """返回整洁的字典格式"""
    album_details = {‘singer‘: name, ‘album‘: album_name}
    return album_details

#已经定义好了字典，现在可以输入几个对应值来检测
album_details_1 = make_album(‘Jay‘, ‘Fantasy‘)
album_details_2 = make_album(‘Taylor Swift‘, ‘Style‘)
album_details_3 = make_album(‘elva‘, ‘the fifth ave‘)
print(album_details_1)
print(album_details_2)
print(album_details_3)

def make_album(name, album_name, number_of_songs = ""):
#number_of_songs 先用空字符代替
    """将歌曲数设置为可选参数"""
    album_details = {‘singer‘: name, ‘album‘: album_name}
    if number_of_songs:
        album_details[‘number of songs‘] = number_of_songs
#只要填入歌曲数，则if语句为真，相应的，会在字典中添加
    return album_details
#定义好以后，可以分别用含歌曲数和不含的两组值来测试

detail_1 = make_album(‘Jay‘, ‘Fantasy‘)
detail_2 = make_album(‘Taylor Swift‘, ‘Style‘, ‘1‘)
print(detail_1)
print(detail_2)

def make_album(name, album_name, number_of_songs):
    """将歌曲数设置为可选参数，在用while语句通过用户输入调用"""
    album_details = {‘singer‘: name, ‘album‘: album_name}
    if number_of_songs:
        album_details[‘number of songs‘] = number_of_songs
    return album_details
#函数定义好以后，就可以与while语句相结合
while True:
    print("\nPlease tell me the details of your favorite album:")
    print("(enter ‘q‘ at any time to quit)")

    name = input("Singer‘s name: ")
    if name == "q":
        break
#break的使用可以使用户操作停止该循环
    album_name = input("Favorite album:")
    if album_name == "q":
        break

    number_of_songs = input("How many songs in the album?")
    if number_of_songs == "q":
        break

    album_details = make_album(name, album_name, number_of_songs)

    print("Thanks for the following information!")
    print(album_details)

原文地址：http://blog.51cto.com/13595859/2090096