一个简单的解决方案是这样的

data = {"John Doe": 100, "john": 50}
new_data = {}
for name, amount in data.items():
    first_name = name.lower().split(" ")[0]
    (current_names, current_amount) = new_data.get(first_name, [[], 0])
    current_names.append(name)
    current_amount += amount
    new_data[first_name] = [current_names, current_amount]

new_data
#=> {'john': [['john', 'John Doe'], 150]}

names_and_data = {}
for names, amount in new_data.values():
    joined_names = ", ".join(names)
    names_and_data[joined_names] = amount

names_and_data
#=> {'john, John Doe': 150}

代码段

from collections import defaultdict

dd = defaultdict(list)
for u in users:
    k = u.split()[0].lower()
    dd[k].append(u)

merged = {','.join(names): sum(users[name] for name in names)
          for firstname, names in dd.items()}

解释

In [184]: from collections import defaultdict

In [185]: dd = defaultdict(list)

In [186]: for u in users:
     ...:     k = u.split()[0].lower()
     ...:     dd[k].append(u)
     ...:

In [187]: dd
Out[187]: defaultdict(list, {'john': ['john', 'John Doe']})

然后可以使用此查找表创建合并格式,如下所示

In [188]: merged = {','.join(names): sum(users[name] for name in names)
    ...:            for firstname, names in dd.items()}

In [189]: merged
Out[189]: {'john,John Doe': 150}

join

In [188]: merged = {', '.join(names): sum(users[name] for name in names)
    ...:            for firstname, names in dd.items()}

In [189]: merged
Out[189]: {'john, John Doe': 150}

请注意,这不会区分

jonathan
john
jon
jon-dawg

正如@wim所建议的,这是一个需要一些自定义正则表达式的复杂得多的问题