combine two lists into a dictionary if a pattern matches

Question

I have basically a list of all the files in a folder, which in a simplified version looks like :

file_list = [ 'drug.resp1.17A.tag', 'drug.resp1.96A.tag', 'drug.resp1.56B.tag', 'drug.resp2.17A.tag', 'drug.resp2.56B.tag', 'drug.resp2.96A.tag']

Another list :

drug_list = [ '17A', '96A', '56B']

I want to combine these two list into a dictionary, such that:

dictionary = {
    '17A' : ['drug.resp1.17A.tag' , 'drug.resp2.17A.tag' ], 
    '96A' : ['drug.resp1.96A.tag' , 'drug.resp2.96A.tag' ], 
    '56B' : ['drug.resp1.56B.tag' , 'drug.resp2.56B.tag' ]}

I thought of doing like this but got stuck !

dict_drugs = {}
for file in file_list:
    list_filename = file.split('.')
    for elem in drug_list:
        if elem in list_filename:

What can I do after this to join the elements into a dictionary, or am I doing this completely wrong ?

Answer 1

well you don't need inner loop

>>> file_list = [ 'drug.resp1.17A.tag', 'drug.resp1.96A.tag', 'drug.resp1.56B.tag', 'drug.resp2.17A.tag', 'drug.resp2.56B.tag', 'drug.resp2.96A.tag']
>>> dictonary = {}
... for i in file_list:
...     k = i.split('.')[-2]
...     if k in dictonary:
...         dictonary[k].append(i)
...     else:
...         dictonary[k] = [i]
>>> dictonary
62: {'17A': ['drug.resp1.17A.tag', 'drug.resp2.17A.tag'],
 '56B': ['drug.resp1.56B.tag', 'drug.resp2.56B.tag'],
 '96A': ['drug.resp1.96A.tag', 'drug.resp2.96A.tag']}
>>> 

---

one more check if only needs those values that are present in drug_list

means if file_list contains :

file_list = [ 'drug.resp1.18A.tag', 'drug.resp1.96A.tag', 'drug.resp1.56B.tag', 'drug.resp2.17A.tag', 'drug.resp2.56B.tag', 'drug.resp2.96A.tag']

>>> drug_list = [ '17A', '96A', '56B']
... dictonary = {}
... for i in file_list:
...     k = i.split('.')[-2]
...     if k in drug_list:
...         if k in dictonary:
...             dictonary[k].append(i)
...         else:
...             dictonary[k] = [i]
>>> 

One more way to efficently do upper case:

dictonary = dict(((i,[]) for i in drug_list))

dictonary = {drug: [] for drug in drug_list}  # As @J.F. Sebastian suggested.

for file in file_list:
    k = file.split('.')[-2]
    if k in dictonary:
        dictonary[k].append(file)