如何从列表创建一个字典，只包含键列表和键值对（Python）？

This is an extension of this question: How to split a string within a list to create key-value pairs in Python

这是此问题的扩展：如何在列表中拆分字符串以在Python中创建键值对

The difference from the above question is the items in my list are not all key-value pairs; some items need to be assigned a value.

与上述问题的区别在于我列表中的项目并非都是键值对;某些项目需要分配一个值。

I have a list:

我有一个清单：

list = ['abc=ddd', 'ef', 'ghj', 'jkl=yui', 'rty']

I would like to create a dictionary:

我想创建一个字典：

dict = { 'abc':'ddd', 'ef':1, 'ghj':1, 'jkl':'yui', 'rty':1 }

I was thinking something along the lines of:

我在思考以下几点：

a = {}
for item in list:
   if '=' in item: 
     d = item.split('=')
     a.append(d) #I don't I can do this.
   else:
     a[item] = 1 #feel like I'm missing something here.

4 个解决方案

#1

For each split "pair", you can append [1] and extract the first 2 elements. This way, 1 will be used when there isn't a value:

对于每个拆分“对”，您可以追加[1]并提取前两个元素。这样，当没有值时将使用1：

print dict((s.split('=')+[1])[:2] for s in l)

#2

I would be using something similar to the post you linked.

我会使用与你链接的帖子类似的东西。

d = dict(s.split('=') for s in a)

If you combine what you can learn from this post -- that is to use lists to create dictionaries -- and from using if/else in Python's list comprehension, you can come up with something like this:

如果你结合你可以从这篇文章中学到的东西 - 即使用列表来创建词典 - 以及在Python的列表理解中使用if / else，你可以想出这样的东西：

d = dict(s.split("=", maxsplit=1) if "=" in s else [s, 1] for s in l)

What this does is add 1 to the end of the split list if there is no equal sign in it.

如果没有相同的符号，它的作用是在拆分列表的末尾添加1。

#3

Here are the step-by-step approach.

以下是逐步的方法。

In [50]: mylist = ['abc=ddd', 'ef', 'ghj', 'jkl=yui', 'rty']

In [51]: [element.split('=') for element in mylist]
Out[51]: [['abc', 'ddd'], ['ef'], ['ghj'], ['jkl', 'yui'], ['rty']]

In [52]: [element.split('=') + [1] for element in mylist]
Out[52]: [['abc', 'ddd', 1], ['ef', 1], ['ghj', 1], ['jkl', 'yui', 1], ['rty', 1]]

In [53]: [(element.split('=') + [1])[:2] for element in mylist]
Out[53]: [['abc', 'ddd'], ['ef', 1], ['ghj', 1], ['jkl', 'yui'], ['rty', 1]]

In [54]: dict((element.split('=') + [1])[:2] for element in mylist)
Out[54]: {'abc': 'ddd', 'ef': 1, 'ghj': 1, 'jkl': 'yui', 'rty': 1}

In order to convert your list in line 50 to a dictionary, you will need to convert it to the list in line 53.
要将第50行中的列表转换为字典，您需要将其转换为第53行中的列表。
Line 51. The first step is to split each element in the list by the equal sign. Each element now is transformed into a list of 1- or 2 elements. Notice that some element like 'ef' which does not have equal sign, we will have to fix that
第51行。第一步是用等号分割列表中的每个元素。现在每个元素都转换为1或2个元素的列表。请注意，某些元素如'ef'没有等号，我们将不得不修复它
Line 52. Next, we append 1 to each sub list. That should take care of the sublists with 1 element, but making some sublist 3 element long
第52行。接下来，我们在每个子列表中附加1。这应该照顾带有1个元素的子列表，但是要使一些子列表3元素长
Line 53: We normalize all sublist into 2-element ones by taking just the first two element and discard the third one if applicable. This list now is in the correct format to convert into a dictionary
第53行：我们通过仅取前两个元素将所有子列表标准化为2个元素，并在适用时丢弃第三个元素。此列表现在具有正确的格式以转换为字典
Line 54. The last step is to take this list and convert it into a dictionary. Since the dict class can take a generator expression, we can safely remove the square brackets.
第54行。最后一步是获取此列表并将其转换为字典。由于dict类可以采用生成器表达式，因此我们可以安全地删除方括号。

With that, here is the snippet:

有了这个，这里是片段：

mylist = ['abc=ddd', 'ef', 'ghj', 'jkl=yui', 'rty']
mydict = dict((element.split('=') + [1])[:2] for element in mylist)

#4

input_list = ['abc=ddd', 'ef', 'ghj', 'jkl=yui', 'rty']
output_dict = {}

for item in input_list:
    item_split = item.split('=')
    key = item_split[0]
    value = item_split[1] if len(item_split)>1 else 1
    output_dict[key] = value

a bit more concisely

更简洁一点

for item in input_list:
    i_s = item.split('=')
    output_dict[i_s[0]] = i_s[1] if len(i_s)>1 else 1

This has the advantage that it doesn't append an extra element to each list created by splitting the elements of the input_list. Though, list comprehensions can be faster than a for loop

这样做的好处是，它不会为通过拆分input_list的元素而创建的每个列表附加额外的元素。但是，列表推导可能比for循环更快

#1