一行循环到多行python

Question

I've got trouble reverting below one line loop to multiple lines loop. here is the original code:

sequences = [[[item.strip() for item in itemset.split(",")] for itemset in sequence] for sequence in sequences]

Multiple line loop that I tried:

for sequence in sequences:
 for itemset in sequence:
    for item in itemset.split(","):
       sequences.append(item.strip())

It does not work as the original one. Any idea?

Answer 1

Your original question reassigns the result with the same name of the data ( sequences ). Here, I assign the result to the variable result .

Given that you did not provide sample data, I just made some up ( sequences ).

Your original list comprehension is nested (note the brackets), with each layer creating a separate list.

[[[x.strip() for x in something] for something in something_else] for something_else in sequences] .

I've recreated that structure by creating a new list with each for-loop , appending as it goes along to match the original list comprehension.

# Sample data.
sequences = [['the, quick, brown fox'], ['jumped, over, the lazy dog']]

# Solution.
result = []
for sequence in sequences:
    inner_list = list()
    result.append(inner_list)
    for itemset in sequence:
        inner_list_2 = list()
        inner_list.append(inner_list_2)
        for item in itemset.split(","):
            inner_list_2.append(item.strip())
>>> result
[[['the', 'quick', 'brown fox']], [['jumped', 'over', 'the lazy dog']]]

# Original list comprehension.
>>> [[[item.strip() for item in itemset.split(",")] 
      for itemset in sequence] 
     for sequence in sequences]
[[['the', 'quick', 'brown fox']], [['jumped', 'over', 'the lazy dog']]]