Printing a list of list as columns with an equal amount of space inbetween

Question

I have a list of lists in python, each of the list within the list have the same number of elements.

sample_list = [['1','22222222222222222','333'],
               ['111111111','2','3'],
               ['1','2','3']]

I want to print out the elements in the list so that they look like this.

1          22222222222222222  333 
111111111  2                  3
1          2                  3

In between the longest item to the next column there will be 2 spaces. So in the 2nd row first column the series of 1s continue and another 2 spaces later is when the next column continues. I won't know the exact length of each element so just using tabs(\t) won't work. How can I print the nested list into a table of columns separated by 2 spaces?

Edit : I want to as much as possible avoid external modules and I need it to be in python 2

You could loop through the list and store the longest lengths and then perform https://docs.python.org/3/library/stdtypes.html#str.ljust — Anton vBR, Dec 12 '17 at 09:18
There are just, so many packages that tabulate data for you. — cs95, Dec 12 '17 at 09:18
https://stackoverflow.com/questions/9535954/printing-lists-as-tabular-data — Uri Hoenig, Dec 12 '17 at 09:22
The question includes headers for the rows and columns. I want my headers to only be used in distinguishing the columns — eclipse, Dec 12 '17 at 10:53

Anton vBR · Accepted Answer · 2017-12-12T11:04:24.470

Something like this:

sample_list = [['1','22222222222222222','333'],
               ['111111111','2','3'],
               ['1','2','3']]

Alternative 1:

# Store max lengths
l = [len(max(i, key=len)) for i in zip(*sample_list)]

for item in sample_list:
    for idx in range(len(l)):
        print(item[idx].ljust(l[idx]), end='  ')
    print()

Alternative 2 (less readable but no artifacts)

# Store max lengths
l = [len(max(i, key=len)) for i in zip(*sample_list)]

print('\n'.join('  '.join(item[i].ljust(l[i]) for i in range(len(l))) 
              for item in sample_list))

Alternative 1 (python2):

# Store max lengths
l = [len(max(i, key=len)) for i in zip(*sample_list)]

for item in sample_list:
    for idx in range(len(l)):
        print item[idx].ljust(l[idx]), "",
    print

1          22222222222222222  333  
111111111  2                  3    
1          2                  3

@eclipse sure... but you should probably try to use solution 2 as it doesn't create artifacts. Extra space and row in end — Anton vBR, Dec 12 '17 at 11:04

Printing a list of list as columns with an equal amount of space inbetween

1 Answers1