convert list of list to dictionary - python-3.x

Question

I have a text file below:
A test B echo C delete
A test B echo C delete D modify
A test B echo C delete
I want to parse the text file above, translate to list of list, and then to a dictionary.
Expected list of list is:
[['A', 'test', 'B', 'echo', 'C', 'delete'], ['A', 'test', 'B', 'echo', 'C', 'delete', 'D', 'modify'], ['A', 'test', 'B', 'echo', 'C', 'delete']]
Final result for dictionary is:
[{'A':'test','B':'echo','C':'delete'},{'A':'test','B':'echo','C':'delete','D': 'modify'},{'A':'test', 'B':'echo', 'C':'delete'}]
This is my script:
#!/usr/bin/python3
def listToDict(list):
listDict = {list[i]: list[i + 1] for i in range (0, len(list), 2)}
return listDict
def parse_file(filepath):
string_to_listoflist = []
with open(filepath, 'r') as file_object:
lines = file_object.readlines()
for line in lines:
string_to_listoflist.append(line.rstrip().split())
dictionary = listToDict(string_to_listoflist)
print(dictionary)
if __name__ == '__main__':
filepath = 'log.txt'
parse_file(filepath)
with the above script will produce an error below:
Traceback (most recent call last):
File "parse.py", line 19, in <module>
parse_file(filepath)
File "parse.py", line 14, in parse_file
dictionary = listToDict(string_to_listoflist)
File "parse.py", line 4, in listToDict
listDict = {list[i]: list[i + 1] for i in range (0, len(list), 2)}
File "parse.py", line 4, in <dictcomp>
listDict = {list[i]: list[i + 1] for i in range (0, len(list), 2)}
TypeError: unhashable type: 'list'
Now I create another loop in the list of list below:
#!/usr/bin/python3
def listToDict(list):
listDict = {list[i]: list[i + 1] for i in range (0, len(list), 2)}
return listDict
def parse_file(filepath):
string_to_listoflist = []
dictionary = {}
with open(filepath, 'r') as file_object:
lines = file_object.readlines()
for line in lines:
string_to_listoflist.append(line.rstrip().split())
for e in string_to_listoflist:
dictionary = listToDict(e)
print(dictionary)
if __name__ == '__main__':
filepath = 'log.txt'
parse_file(filepath)
The script above will produce unexpected result even I define the dictionary variable before the loop:
{'A': 'test', 'B': 'echo', 'C': 'delete'}
Then change the position of print command as below:
#!/usr/bin/python3
def listToDict(list):
listDict = {list[i]: list[i + 1] for i in range (0, len(list), 2)}
return listDict
def parse_file(filepath):
string_to_listoflist = []
dictionary = {}
with open(filepath, 'r') as file_object:
lines = file_object.readlines()
for line in lines:
string_to_listoflist.append(line.rstrip().split())
for e in string_to_listoflist:
dictionary = listToDict(e)
print(dictionary)
if __name__ == '__main__':
filepath = 'log.txt'
parse_file(filepath)
Unexpected result for the script above is:
{'A': 'test', 'B': 'echo', 'C': 'delete'}
{'A': 'test', 'B': 'echo', 'C': 'delete', 'D': 'modify'}
{'A': 'test', 'B': 'echo', 'C': 'delete'}
Can anyone help how to resolve my issue?
Thanks

Answer 1

In your first attempt, your variable string_to_listoflist is a list of lists.
When you pass it to your function listToDict, the function iterates on the parent level of the list instead of iterating over each list within the parent list. Thus, the first entry attempted in the dictionary is
['A', 'test', 'B', 'echo', 'C', 'delete']:['A', 'test', 'B', 'echo', 'C', 'delete', 'D', 'modify']
rather than your intended
'A':'test'
This causes the error you observe TypeError: unhashable type: 'list' since a list (mutable) is attempted to be used as a key in a dictionary, which requires immutable keys.
Adding the extra loop surrounding each element of the parent list is the correct way to resolve this. However, if you want your final result to be inside a list, you simply need to append the result to a list.
In other words, perhaps the following
dictionaries=[]
for e in string_to_listoflist:
dictionary = listToDict(e)
dictionaries.append(dictionary)
print(dictionaries)

Answer 2

You can use re module to obtain your desired dict.
For example:
import re
with open('file.txt', 'r') as f_in:
out = [dict(re.findall(r'([A-Z]+) ([^\s]+)', line)) for line in f_in]
print(out)
Prints:
[{'A': 'test', 'B': 'echo', 'C': 'delete'}, {'A': 'test', 'B': 'echo', 'C': 'delete', 'D': 'modify'}, {'A': 'test', 'B': 'echo', 'C': 'delete'}]