CODEWITHSUNDEEP
pythondictionary-comprehension
user6037143
user6037143

Reputation: 566

How can I increment the value of a variable within dictionary comprehension

start = 0
limit = 100
count = 10
total_count = 1000
pages = {}
for i in range(1, count+1):
    pages[i] = start
    start += limit
print pages
{1: 0, 2: 100, 3: 200, 4: 300, 5: 400, 6: 500, 7: 600, 8: 700, 9: 800, 10: 900}

How can I achieve the same result using dictionary comprehension? I can't seem to be able to increment the value of variable 'start' after each iteration with dict comprehension.

Is it possible to achieve the same result comprehension?

Upvotes: 0

Views: 855

Answers (3)

Guy_g23
Guy_g23

Reputation: 385

I ran into this question when I was looking for a solution to increment a variable which I want to be a part of each key in the dictionary. The solutions here didn't assist in my case so I used Python's enumerate() method for that. Here's what my solution would look like for the question posted here:

    start = 0
    limit = 100
    count = 10
    pages2 = {(j + 1): start + i * limit for i, j in enumerate(range(count))}
    print(pages2)

Upvotes: 0

zondo
zondo

Reputation: 20336

Use mathematics:

pages = {(i+1): 100 * i for i in range(count)}

Since start starts at zero and keeps adding 100, we can use multiplication to find where it should be at each point. If start and limit aren't always going to be what they are here, you can still do this:

pages = {(i+1): start + (limit * i) for i in range(count)}

Upvotes: 2

Carsten
Carsten

Reputation: 18446

start = 0
limit = 100
count = 10
pages2 = {(i + 1): start + i * limit for i in range(count)}
print pages2

Upvotes: 1

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