how to incorporate 'if' condition into for loop statement

Question

data = [(1,'hi'),(2,'hello'),(3,'hi'),(4,'hi'),(5,'hello'),(6,'hello'), 
(7,'hi'),(8,'hello')]
new_data = []
for i in data:
    if i[1] == 'hi':
        new_data.append(i)
print(new_data)

output:[(1, 'hi'), (3, 'hi'), (4, 'hi'), (7, 'hi')]

i am a beginner in python. i want the same output but want to reduce the amount of code in the'For' loop and be more efficient.

Your code is easy to understand, and does exactly what it should do. The few extra lines shouldn't matter too much. — Stef van der Zon, Sep 04 '18 at 09:00

score 1 · Accepted Answer · answered Sep 04 '18 at 09:00

1

While your loop is fine, you can use a list comprehension:

new_data = [i for i in data if i[1] == 'hi']

answered Sep 04 '18 at 09:00

user2390182

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score 0 · Answer 2 · answered Sep 04 '18 at 09:05

You can use a list comprehension and a filter to write in on one line. There is a good explanation on filters available at this question. Using filters you can make use of lazy evaluation, which benefits the execution time.

data = [(1,'hi'),(2,'hello'),(3,'hi'),(4,'hi'),(5,'hello'),(6,'hello'), (7,'hi'),(8,'hello')]
new_data = list(filter(lambda i: i[1] == 'hi', data))

Output

[(1, 'hi'), (3, 'hi'), (4, 'hi'), (7, 'hi')]

how to incorporate 'if' condition into for loop statement

2 Answers2