任务目标：

Given: an array containing hashes of names

Return: a string formatted as a list of names separated by commas except for the last two names, which should be separated by an ampersand.

Example:

namelist([ {‘name‘: ‘Bart‘}, {‘name‘: ‘Lisa‘}, {‘name‘: ‘Maggie‘} ])
# returns ‘Bart, Lisa & Maggie‘

namelist([ {‘name‘: ‘Bart‘}, {‘name‘: ‘Lisa‘} ])
# returns ‘Bart & Lisa‘

namelist([ {‘name‘: ‘Bart‘} ])
# returns ‘Bart‘

namelist([])
# returns ‘‘

解决方案：

def namelist(names):
    str = ""
    if len(names) == 0:
        pass
    elif len(names) == 1:
        str = str + (names[0][‘name‘])
    else:
        for each in names[0:-2]:
            str = str + (each[‘name‘]) + (‘, ‘)
        str = str + (names[-2][‘name‘]) + (‘ & ‘) + (names[-1][‘name‘])
    return str

codewars上的解决方案：from ezetter

def namelist(names):
    if len(names)==0: return ‘‘
    if len(names)==1: return names[0][‘name‘]
    return ‘, ‘.join([n[‘name‘] for n in names[:-1]]) + ‘ & ‘ + names[-1][‘name‘]

参考资料

http://www.linuxidc.com/Linux/2011-09/42950.htm

[codewars 1] Format a string of names like 'Bart, Lisa & Maggie'.