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Comments on How to group a flat list of attributes into a nested lists?

Post

How to group a flat list of attributes into a nested lists?

+2
−2

I have a flat list where each item is the key and value for an attribute. I want to transform this into a nested list where each attribute is a sublist.

Example input:

[
  "attr1 apple 1",
  "attr1 banana 2",
  "attr2 grapes 1",
  "attr2 oranges 2",
  "attr3 watermelon 0"
]

The output should be:

[
  [
    "attr1 apple 1",
    "attr1 banana 2",
  ],
  [
    "attr2 grapes 1",
    "attr2 oranges 2",
  ],
  [
    "attr3 watermelon 0"
  ]
]

I tried this program, but the result is incorrect.

import re

# regex pattern definition
pattern = re.compile(r'attr\d+')

# Open the file for reading
with open(r"file path") as file:
    # Initialize an empty list to store matching lines
    matching_lines = []

    # reading each line 
    for line in file:
        # regex pattern match
        if pattern.search(line):
            # matching line append to the list
            matching_lines.append(line.strip())

# Grouping the  elements based on the regex pattern

#The required list
grouped_elements = []

#Temporary list for sublist grouping
current_group = []

for sentence in matching_lines:
    if pattern.search(sentence):
        current_group.append(sentence)
    else:
        if current_group:
            grouped_elements.append(current_group)
        current_group = [sentence]

if current_group:
    grouped_elements.append(current_group)

# Print the grouped elements
for group in grouped_elements:
    print(group)

I am getting this output:

[
    'attr1 apple 1',
    'attr1 banana 2', 
    'attr2 grapes 1',
    'attr2 oranges 2', 
    'attr3 watermelon 0'
]
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4 comment threads

Post code in code reviews (1 comment)
Get rid of the code (1 comment)
I want to answer (1 comment)
Needs more focus (2 comments)
I want to answer

The answer is something like:

nested = []
attrs = ['attr1', 'attr2', 'attr3']
for a in attrs:
    u = []
    for i in flat:
        if i.startswith('attr1'):
            u.append(i)
    if u:
        nested.append(u)

print(nested)

Wish I could post a full answer, but unfortunately it's closed.