为什么这本词典会这样生成？

Question

我正在制作一个简单的应用程序来安排联赛比赛。我知道比赛的周数，那一周的每支球队都需要一场比赛。我还没说完，但我正在测试它，输出会很奇怪。

def scheduleMaker(dicty):
    weeks_to_sched = int(input("How many weeks?"))
    #weeks count
    weeks_count = [list(range(1, (weeks_to_sched + 1)))]
    schedule = {}
    #for every week of the season
    for x in weeks_count:
        #add a entry in the dict for this week
        schedule[f"Week {x}"] = {}
        #every team that week needs a matchup
        for j in names:
            #this team needs to be added to week 1 with a matchup
            schedule[f"Week {x}"][j] = [j]
    print(schedule)

scheduleMaker(teams)

我想要为每周创建一个字典，然后是每周字典中的键：值（匹配项）。我在代码的第一行遇到问题。我得到：

{'Week [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]': {}

代替：

{'Week 1': {}, 'Week 2': {}, 'Week 3: {}', etc}

Answer 1

问题出在这里：

weeks_count = [list(range(1, (weeks_to_sched + 1)))]

它在列表内创建一个列表，因此当您迭代 weeks_count 时，您那里只有一个元素（整个范围的一个元素）。

改为：

weeks_count = list(range(1, (weeks_to_sched + 1)))

请记住，在您的情况下，您不必将范围转换为列表（当您想要多次迭代范围时，转换为列表很有用），因此您可以直接使用它。

weeks_count = range(1, (weeks_to_sched + 1))

Answer 2

首先，您需要学习如何调试代码和查找错误。添加简单的打印行将帮助您发现问题

print(weeks_count)
print(x)

#produces 
[[1, 2, 3]]
[1, 2, 3]

这意味着x 等于整个数组而不是预期的int。那是因为您在列表中添加了额外的括号并使其成为数组，其中列表作为数组的第一个元素

    # not ok
    weeks_count = [list(range(1, (weeks_to_sched + 1)))]
    # ok
    weeks_count = list(range(1, (weeks_to_sched + 1)))
    # best
    weeks_count = range(1, weeks_to_sched + 1)

但您也不需要保留 week_count 列表，因为您可以直接遍历范围（代码如下）

我还建议不要丢失输入、一些全局 names 变量和将计划创建到 1 个函数中的逻辑。更好的方法是将所有必需的参数传递给这个函数，这样它就有一个责任

最终代码和输出：

def scheduleMaker(weeks_to_sched, names):
    schedule = {}
    for weekNum in range(1, weeks_to_sched + 1):
        schedule[f"Week {weekNum}"] = {}
        for j in names:
            schedule[f"Week {weekNum}"][j] = [j]
    print(schedule)

weeks_to_sched = int(input("How many weeks?"))
scheduleMaker(weeks_to_sched, ['a', 'b', 'c'])

{'Week 1': {'a': ['a'], 'b': ['b'], 'c': ['c']}, 'Week 2': {'a': ['a'], 'b': ['b'], 'c': ['c']}, 'Week 3': {'a': ['a'], 'b': ['b'], 'c': ['c']}}

Answer 3

您需要使用range() 函数才能按照您描述的方式循环。

尝试这样做

def scheduleMaker():
    weeks_to_sched = int(input("How many weeks?"))
    schedule = {}
    #for every week of the season
    for x in range(1, weeks_to_sched + 1):
        #add a entry in the dict for this week
        schedule[f"Week {x}"] = {}
        #every team that week needs a matchup
        for j in names:
            #this team needs to be added to week 1 with a matchup
            schedule[f"Week {x}"][j] = [j]
    print(schedule)