[英]Creating a dictionary from a list of strings
I have a list of strings 我有一个字符串清单
list = ['2(a)', '2(b)', '3', '3(a)', '1d', '5']
where it is intentional that the 1d, 3, and 5 don't involve parentheses. 故意使1d,3和5不包含括号。
I would like to create a dictionary which looks like this: 我想创建一个像这样的字典:
dict = {'2': 'a', '2': 'b', '3': 'a', '1': 'd'}
or 要么
dict = {'2': ['a', 'b'], '3': ['a'], '1': ['d']}.
Essentially, ignore those strings without a letter az. 本质上,忽略那些不带字母az的字符串。 I've used regular expressions to extract from the top list the following: 我使用正则表达式从顶部列表中提取以下内容:
['a', 'b', 'a', 'd'],
but this hasn't helped me much in forming my dictionary easily. 但这对我轻松地编写字典没有太大帮助。
Any help is much appreciated. 任何帮助深表感谢。
Since a dictionary can't contain duplicate keys, use a defaultdict
: 由于字典不能包含重复的键,请使用defaultdict
:
import collections
l = ['2(a)', '2(b)', '3', '3(a)', '1c', '5']
d = collections.defaultdict(list)
for item in l:
num = ''.join(c for c in item if c.isdigit())
word = ''.join(c for c in item if c.isalpha())
if word and num:
d[num].append(word)
Result: 结果:
>>> print(d)
defaultdict(<class 'list'>, {'2': ['a', 'b'], '1': ['c'], '3': ['a']})
This is a good time to use setdefault()
for a dictionary to define the structure of your dictionary. 这是将setdefault()
用于字典以定义字典结构的好时机。 The first part involves capturing the numbers from the elements using a regex that captures all numbers. 第一部分涉及使用捕获所有数字的正则表达式从元素捕获数字。 That list
is then concatenated using join()
. 然后使用join()
连接该list
。
We then extract only alphabet characters using either a list comprehension -> [j for j in i if j.isalpha()]
, or pass as a generator j for j in i if j.isalpha()
( generator in our case, joining the elements as a string
together once again ). 然后,我们只使用列表 [j for j in i if j.isalpha()]
-> [j for j in i if j.isalpha()]
则提取字母字符,或者j for j in i if j.isalpha()
生成器 j for j in i if j.isalpha()
传递( 在本例中为generator, 再次 将这些元素作为 string
合并在一起 )。
Lastly a check to see that both key
and value
exist so that we can set our dictionary to be of this format -> { '' : [] , ...}
最后检查一下是否存在key
和value
,以便我们可以将字典设置为以下格式-> { '' : [] , ...}
import re
def to_dict(l):
d = {}
for i in l:
key = re.findall(r'\d+', i)
value = ''.join(j for j in i if j.isalpha())
if key and value:
d.setdefault(''.join(key), []).append(value)
return d
Sample output: 样本输出:
l = ['2(a)', '2(b)', '3', '3(a)', '1c', '5']
print to_dict(l)
>>> {'1': ['c'], '3': ['a'], '2': ['a', 'b']}
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