Quick question... searched and didn't find anything. I have this list:
list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10]
I want to have each value repeated 3 more times in the same list... How do I do so? I tried some for loops that .append to the list but things got messy. I ended up getting some list in list that were in lists. I have a feeling .append is not right for this scenario.
In [1]: my_list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10]
In [2]: sorted(my_list * 3)
Note that you should not use list
as a variable name, because it shadows the keyword list
.
One other option is to use numpy
:
In [8]: import numpy as np
In [9]: np.repeat(my_list, 3)
Use nested loops in a list comprehension.
>>> [x for x in L for y in range(4)]
[1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10]
You can try something like this!
baselist = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10]
[z for y in [[x]*4 for x in baselist] for z in y]
This is equivalent to:
listofLists = []
for x in baseList:
listofLists.append([x]*4)
finalList = []
for y in listofLists:
for z in y:
finalList.append(z)
You see, the list comprehension simply shortens the logic, but whether it's more readable will depend on your grasp of comprehension syntax.
You could do like this,
>>> lst = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10]
>>> [j for i in lst for j in [i,i,i,i]]
[1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10]
Another itertools
variation using the flatten
recipe
>>> m = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10]
>>> import itertools
>>> list(itertools.chain.from_iterable(itertools.izip(m,m,m,m)))
[1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10]
>>>
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