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María Paula
María Paula

Reputation: 1

Removing the first char of some words on a list in Python

I have the following list.

filtered_sent = ['colombia', 'nnueva', 'revolución', 'nindustrial', 'npropuestas', 'foco', 'tecnologías', 'convergentes', 'ne', 'industrias', 'nvolumen', 'ncolombia', 'nartista', 'federico', 'uribe', 'npropuestas', 'foco', 'tecnologías', 'convergentes', 'ne', 'industrias', 'ntomo', 'ncolombia', 'nueva', 'nrevolución', 'nindustrial', 'vicepresidencia', 'república', 'colombia', 'ministerio', 'ciencia', 'tecnología', 'innovación', 'elías', 'niño', 'ruiz', 'jean', 'paul', 'allain', 'josé', 'alejandro', 'montoya', 'juan', 'luis']

I want to remove the first character of each word that starts with 'n'. (for example: 'nnueva', 'nartista', 'nindustrial', etc.)

I tried this but it is removing the first character of the word from ALL words of the list:

lista_A = [] 
for it in filtered_sent:
    for j in it:
        if j[0] == 'n':
            lista_A.append(it[1:])

Upvotes: 0

Views: 84

Answers (5)

dmertins
dmertins

Reputation: 578

Answering the question, the mistake is the second for loop ("for j in it:"). There's no need to iterate through each letter of each word. Instead of checking only if the first letter of each word is equal to 'n', your code is checking if any letter of the word is equal to 'n'. At each iteration of the inner for loop, both j and j[0] are a reference to the same specific letter.

You can add some print statements to your code to better understand what is happening.

lista_A = [] 
for it in filtered_sent:
    for j in it:
        print(f'it: {it}')
        print(f'j: {j}')
        print(f'j[0]: {j[0]}')
        if j[0] == 'n':
            lista_A.append(it[1:])

Try removing the second for loop, and change the if clause to check the first character of the word:

lista_A = [] 
for it in filtered_sent:
  if it[0] == 'n':
    lista_A.append(it[1:])

Upvotes: 0

Nil Gurung
Nil Gurung

Reputation: 21

There is some logical issue with your code in if block.

It's better to compare both index and first char of the word.

This code works.

lista_A = [] 
for it in filtered_sent:
    for i,j in enumerate(it):
        if j == 'n' and i == 0:
            lista_A.append(it)
        
print(lista_A)

Upvotes: 1

Daniel
Daniel

Reputation: 1

You can try:

list(map(lambda word: word[1:] ,filter(lambda x:(x[0]=="n"),filtered_sent)))

Upvotes: 0

Jaime
Jaime

Reputation: 1631

You could try:

filtered = [i[1:] if i[0] == 'n' else i for i in filtered_sent]

Upvotes: 1

xjcl
xjcl

Reputation: 15309

Using a built-in str function:

new_list = [word.removeprefix('n') for word in filtered_sent]

Upvotes: 0

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