Converting integer to digit list

Question

What is the quickest and cleanest way to convert an integer into a list    For example  change 132 into  1 3 2  and 23 into  2 3   I have a variable which is an int  and I want to be able to compare the individual digits so I thought making it into a list would be best  since I can just do int number 0    int number 1   to easily convert the list element back into int for digit operations

User · Answer

There are already great methods already mentioned on this page, however it does seem a little obscure as to which to use. So I have added some mesurements so you can more easily decide for yourself:

A large number has been used (for overhead) 1111111111111122222222222222222333333333333333333333

Using `map(int, str(num))`:

import timeit

def method():
    num = 1111111111111122222222222222222333333333333333333333
    return map(int, str(num))

print(timeit.timeit("method()", setup="from __main__ import method", number=10000)

Output: 0.018631496999999997

Using list comprehension:

import timeit

def method():
    num = 1111111111111122222222222222222333333333333333333333
    return [int(x) for x in str(num)]

print(timeit.timeit("method()", setup="from __main__ import method", number=10000))

Output: 0.28403817900000006

Code taken from this answer

The results show that the first method involving inbuilt methods is much faster than list comprehension.

The "mathematical way":

import timeit

def method():
    q = 1111111111111122222222222222222333333333333333333333
    ret = []
    while q != 0:
        q, r = divmod(q, 10) # Divide by 10, see the remainder
        ret.insert(0, r) # The remainder is the first to the right digit
    return ret

print(timeit.timeit("method()", setup="from __main__ import method", number=10000))

Output: 0.38133582499999996

Code taken from this answer

The `list(str(123))` method (does not provide the right output):

import timeit

def method():
    return list(str(1111111111111122222222222222222333333333333333333333))
    
print(timeit.timeit("method()", setup="from __main__ import method", number=10000))

Output: 0.028560138000000013

Code taken from this answer

The answer by Duberly González Molinari:

import timeit

def method():
    n = 1111111111111122222222222222222333333333333333333333
    l = []
    while n != 0:
        l = [n % 10] + l
        n = n // 10
    return l

print(timeit.timeit("method()", setup="from __main__ import method", number=10000))

Output: 0.37039988200000007

Code taken from this answer

Remarks:

In all cases the map(int, str(num)) is the fastest method (and is therefore probably the best method to use). List comprehension is the second fastest (but the method using map(int, str(num)) is probably the most desirable of the two.

Those that reinvent the wheel are interesting but are probably not so desirable in real use.

User · Answer

The shortest and best way is already answered  but the first thing I thought of was the mathematical way  so here it is   def intlist n       q   n     ret          while q    0          q  r   divmod q  10    Divide by 10  see the remainder         ret insert 0  r    The remainder is the first to the right digit     return ret  print intlist 3  print  -  print intlist 10  print  --  print intlist 137    It s just another interesting approach  you definitely don t have to use such a thing in practical use cases

User · Answer

Use list on a number converted to string   In  1    int x  for x in list str 123    Out 2    1  2  3

User · Answer

num   list str 100   index   len num  while index  gt  0      index -  1     num index    int num index   print num    It prints  1  0  0  object

User · Answer

Convert the integer to string first  and then use map to apply int on it    gt  gt  gt  num   132  gt  gt  gt  map int  str num       note  This will return a map object in python 3   1  3  2    or using a list comprehension    gt  gt  gt   int x  for x in str num    1  3  2

User · Answer

If you have a string like this   123456  and you want a list of integers like this   1 2 3 4 5 6   use this    gt  gt  gt s    123456       gt  gt  gt list1    int i  for i in list s    gt  gt  gt print list1    1 2 3 4 5 6    or if you want a list of strings like this    1   2   3   4   5   6    use this    gt  gt  gt s    123456       gt  gt  gt list1   list s   gt  gt  gt print list1     1   2   3   4   5   6

User · Answer

you can use   First convert the value in a string to iterate it  Them each value can be convert to a Integer value   12345  l     int item  for item in str value

User · Answer

By looping it can be done the following way     num1  int input  Enter the number    sum1   num1  making a alt int to store the value of the orginal so it wont be affected y       making a list  while True      if sum1  0   checking if the number is not zero so it can break if it is         break     d   sum1 10  last number of your integer is saved in d     sum1   int sum1 10   integer is now with out the last number ie 4320 10 become 432     y append d    appending the last number in the first place  y reverse   as last is in first   reversing the number to orginal form print y    Answer becomes   Enter the number2342  2  3  4  2

User · Answer

gt  gt  gt list map int  str number      number is a given integer   It returns a list of all digits of number

User · Answer

n   int raw input  n       def int to list n       l          while n    0          l    n   10    l         n   n    10     return l  print int to list n

[python] Converting integer to digit list

Using `map(int, str(num))`:

Using list comprehension:

The "mathematical way":

The `list(str(123))` method (does not provide the right output):

The answer by Duberly González Molinari:

Remarks:

Examples related to python

Examples related to list

Examples related to integer

Examples related to type-conversion

[python] Converting integer to digit list

Using map(int, str(num)):

Using list comprehension:

The "mathematical way":

The list(str(123)) method (does not provide the right output):

The answer by Duberly González Molinari:

Remarks:

Examples related to python

Examples related to list

Examples related to integer

Examples related to type-conversion

Using `map(int, str(num))`:

The `list(str(123))` method (does not provide the right output):