my task was to define a function that takes a list of names and returns a dictionary of names the corresponding length of each string (Name). The code worked just fine:

    def toDict(namelist):
            lengths = []
            for i in namelist:
                    lengths.append(len(i))
            namedict = dict(zip(namelist, lengths))
            return namedict
            print(namedict)

However, 2nd part of the task was to do it in one line only and I'm getting stuck a bit there... please help.

CodePudding user response：

One approach is to use a dict comprehension:

namedict = {name: len(name) for name in namelist}

If you need your entire function definition to be on one line, I’d suggest using a lambda:

to_dict = lambda name_list: {n: len(n) for n in name_list}

As mentioned in the comments, even though I personally prefer the lambda approach - and though I feel it’s a solid use case for it - it’s still possible to use a def and have a normal function on a single line; you’ll just need to put the body immediately after the colon : as shown below.

def to_dict(name_list): return {n: len(n) for n in name_list}

CodePudding user response：

Another way:

>>> li = ['one', 'three', 'four']
>>> dict(zip(li, map(len, li)))
{'one': 3, 'three': 5, 'four': 4}

How it works:

1. map applies the function len to each element in li
2. zip forms a tuple of name and length
3. dict takes the tuple and forms a dictionary.