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How do I create an ordered list of 500 tuples and then add data to it?

This is my code using Python 2.7

list1 = [1,2,3,4,5,6,9,10.....1000]

I am trying to create chunks of 500 list data like

chunk_data = [(1,2,3,4,5,...500),(501,502....1000)]

and then I am going to add "data" at the end of each chunk

so it looks like this:

[(1,2...500,'data'),(501,502...1000,'data')]

I tried using zip for this

it = iter(list1)    
chunked_data = zip(*[it]*500)

but i can't add "data" now

from itertools import repeat
chunked_data = zip(*[it]*500,repeat("data")) #Gives Error about adding arguments after unpacking function values !!

I was unable to write this code below, although it will work

chunked_data = zip(it,it,it...(500 times),repeat("data")]

So how do I go about doing this?

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5 answers


You can create a list of positional arguments and then unpack it:

args = [it] * 500 + [repeat('data')]
chunked_data = zip(*args)

This is essentially a modified grouper

recipe from the documentation itertools

.

This works great:

In [17]: it = iter('0123456789')

In [18]: args = [it] * 5 + [repeat('data')]

In [19]: list(zip(*args))
Out[19]: [('0', '1', '2', '3', '4', 'data'), ('5', '6', '7', '8', '9', 'data')]


Alternative solution:

[tuple(list1[i:i+500]) + ('data',) for i in range(0, len(list1), 500)]

More information can be found on the page.

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[tuple(list1[i:i+500]+['data']) for i in xrange(0, len(list1), 500)]


You can change 500 and expand it for any fragment size

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A function that provides your output

def chunks_with_data(l, n):
    return [tuple(l[i:i + n])+("data",) for i in range(0, len(l), n)]

>>>chunks_with_data(range(1000), 500)
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But it can be very long!

base_lst = [x for x in range(1, 1001)]
lst = [tuple(base_lst[x:x+500]+['Data']) for x in range(500)]
print(lst)
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Here is my question on this issue. It returns 500 items from list ( [(1...500),(501...1000)]

) and adds data

:

l = [x for x in range(1, 1001)]
out_l = [tuple(l[i:i+500] + ['data']) for i in xrange(0, len(l), 500)]
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