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'
]

posted 2 months ago

CC BY-SA 4.0

2mo ago by matthewsnyder‭

aditya98‭

79 reputation 7 0 9 1