Sum one number to every element in a list or array in Python

Question

Here I go with my basic questions again  but please bear with me   In Matlab  is fairly simple to add a number to elements in a list   a    1 1 1 1 1  b   a   1   b then is  2 2 2 2 2   In python this doesn t seem to work  at least on a list   Is there a simple fast way to add up a single number to the entire list   Thanks

User · Accepted Answer

if you want to operate with list of numbers it is better to use NumPy arrays   import numpy a    1  1  1  1  1  ar   numpy array a  print ar   2   gives   3  3  3  3  3

User · Answer

You can also use map   a    1  1  1  1  1  b   1 list map lambda x  x   b  a     It gives    2  2  2  2  2

User · Answer

If you don t want list comprehensions     a    1 1 1 1 1  b      for i in a      b append i 1

User · Answer

using List Comprehension    gt  gt  gt  L    1  5  gt  gt  gt   x 1 for x in L   2  2  2  2  2   gt  gt  gt     which roughly translates to using a for loop    gt  gt  gt  newL       gt  gt  gt  for x in L          newL   x 1        gt  gt  gt  newL  2  2  2  2  2    or using map    gt  gt  gt  map lambda x x 1  L   2  2  2  2  2   gt  gt  gt

User · Answer

try this   I modified the example on the purpose of making it non trivial   import operator import numpy as np  n 10 a   list range n   a1    1  len a  an   np array a    operator add is almost more than two times faster   timeit map operator add  a  a1    than adding with numpy   timeit an 1

[python] Sum one number to every element in a list (or array) in Python

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