为什么我的 for 循环没有将所有值添加到字典中？

Question

def biggest_family(fil):
    with open(fil) as file:
        name = {}
        ans = {}
        text = file.read().split("\n")
        for i in range (0 , len(text)-1):
            first = text[i].split()
            name[first[0]] = first[1]        
        for b in name:
            if name[b] in ans:
                ans[name[b]] += 1
            else:
                ans[name[b]] = 1
        print(ans)
           

输出应为家庭的姓氏的字典，并且是列表中存在的次数。由于某种原因，它对某些数据集非常有效，而其他数据集则是一个数字。如您在下面的图片中所看到的，它在第一个测试中以正确的数量打印了辛普森一家和格里芬斯，但在其上方的兰尼斯特家族中没有打印出来。

Answer 1

问题是Cersei Smith在您的第一个循环中的名称字典中替换cersei lannister。无法重复字典键，因此您不能有两个不同的cersei条目。

不需要name字典，只需在该循环中创建ans字典即可。

def biggest_family(fil):
    with open(fil) as file:
        text = file.read().split("\n")
    ans = {}
    for full_name in text[:-1]:
        first_name, last_name = full_name.split()
        if last_name in ans:
            ans[last_name] += 1
        else:
            ans[last_name] = 1   
    print(ans)

Answer 2

您的问题似乎表明输出应该是打印文本而不是字典。毫无疑问，有一些无法理解的理解可以用更少的代码来完成此操作，但让我们采取逐步的方法：

def biggest_family(fil):
    with open(fil) as family:
        d = dict() # empty dictionary
        hi_count = 0 # keep track of the hi number of family members
        for line in map(str.strip, family): # iterate of the file line by line
            forename, surname = line.split() # get the surname and forename
            d.setdefault(surname, []).append(forename) # append to a list value against a surname key in the dictionary
            if (l_ := len(d[surname])) > hi_count: # check the hi count
                hi_count = l_
        output = [] # empty list
        for k, v in d.items(): # iterate over the dictionary looking for families equal to the hi count
            if len(v) == hi_count: # we're interested in this one
                output.append(f'{k} family: {" ".join(sorted(v))}')
        for line in sorted(output): # looks like the output needs to be sorted
            print(line)

biggest_family('family.txt')

我创建了一个名为 family.txt 的文件，其中包含您问题中显示的内容。其输出将是：

Lannister family: Cersei Jaime Tyrion
Stark family: Arya Catelyn Ned