Format output of a list in to columns

Question

For the purpose of keeping to this short, Ill excluse the entire code, this is more of a pythonic question. Lets pretend that theres a list called "plist". This list has a rage of N...

print(plist[0:4])
print(plist[4:8])
print(plist[8:12])
print(plist[12:16])
print(plist[16:20])
print(plist[20:24])

...

What Im trying to do is imitate this behavior, basically printing out my list into 4 columns... simple enough right?

also, its a straight up list,nothing nested Using the len() we can get the number to use for range Im just im banging my head trying to figure out how to use a loop that will use the len() as the max value ...??

Also, I know you can use slice but there's some logic math involved since the length can be od or even and bahhhh.... my brain hurt.

---

EXAMPLE OF OUTPUT:

 >>> plist
[178433, 207110, 204805, 140038, 177544, 179979, 166668, 177602, 140559, 170642, 208019, 150809, 161434, 177565, 134814, 175221, 172577, 204708, 177573, 146604, 177694, 180041, 156088, 180064, 172478, 177599, 172608, 141761, 156226, 171718, 170056, 141513, 208082, 162509, 171726, 132431, 204753, 178386, 179923, 178390, 171864, 204772, 207049, 134368, 148961, 169828, 131301, 171754, 144107, 206308, 178415, 151920, 206323, 207988, 134334, 141431, 206328, 176508]

And desired output

forExmple()
[178433, 207110, 204805, 140038]
[177544, 179979, 166668, 177602]
[140559, 170642, 208019, 150809]
[161434, 177565, 134814, 175221]
[172577, 204708, 177573, 146604]
[177694, 180041, 156088, 180064]

UPDATE

AHA! okay so I figured if I break the list it more list ... durppp Ican chuck it... quick google search.... so I got this..

chunks = [plist[x:x+4] for x in range(0, len(plist))]

THEN, By using lenght of chuncks I can iterate throughthat number as therange,,,

for i in range(0, len(chunks)):
    print(chunks[i])

BOOM... any better way?

Answer 1

This is definitely not what you want!

chunks = [plist[x:x+4] for x in range(0, len(plist))]

print(chunks)

Desired output:

[178433, 207110, 204805, 140038]
[177544, 179979, 166668, 177602]
.... and so on

Your output:

[178433, 207110, 204805, 140038],
[207110, 204805, 140038, 177544],
[204805, 140038, 177544, 179979],
...

You see the difference?

You want to split them into sublists of 4. i.e plist[0:4],plist[4:8].. and so on for that you need little bit maths. Don't worry I'll explain it to you!.

Take a look at this code!.

a=[178433, 207110, 204805, 140038, 177544, 179979, 166668, 177602, 140559, 170642, 208019, 150809, 161434, 177565, 134814, 175221, 172577, 204708, 177573, 146604, 177694, 180041, 156088, 180064, 172478, 177599, 172608, 141761, 156226, 171718, 170056, 141513, 208082, 162509, 171726, 132431, 204753, 178386, 179923, 178390, 171864, 204772, 207049, 134368, 148961, 169828, 131301, 171754, 144107, 206308, 178415, 151920, 206323, 207988, 134334, 141431, 206328, 176508]



my_len = len(a)
my_len = (my_len-my_len%4)+4
my_range = my_len//4
print(my_range)

fin_list = [a[i*4:i*4+4] for i in range(my_range)]
for item in fin_list:
    print(item)

Output:

15
[178433, 207110, 204805, 140038]
[177544, 179979, 166668, 177602]
[140559, 170642, 208019, 150809]
[161434, 177565, 134814, 175221]
[172577, 204708, 177573, 146604]
[177694, 180041, 156088, 180064]
[172478, 177599, 172608, 141761]
[156226, 171718, 170056, 141513]
[208082, 162509, 171726, 132431]
[204753, 178386, 179923, 178390]
[171864, 204772, 207049, 134368]
[148961, 169828, 131301, 171754]
[144107, 206308, 178415, 151920]
[206323, 207988, 134334, 141431]
[206328, 176508]

The following lines are needed the most!.

my_len = len(a)
my_len = (my_len-my_len%4)+4
my_range = my_len//4

First my_len will have the length of the list ,here it is 58.

The next line (my_len-my_len%4)+4 what it does you may ask. See we need a range that we can easily split into chunks of size 4 right?

So this means when we have size as 58 we would get

14 four sized sub-lists and 1 two sized list.

[178433, 207110, 204805, 140038]  --> size 4
[177544, 179979, 166668, 177602]  --> size 4
 .
 .
 .
[206328, 176508]       ---> And finally size 2 

Why size 2 in the last one that's because our list size was 58?. So we can split the first 56 elements into 4 item exactly leaving the remaining as ? ----> 2.

So how many sub-lists we have totally? 15. How to get that?

Check this out

>>> my_len= 58
>>> my_len
58
>>> my_len%4
2

So % just gives the remainder. So our remainder here is 2.

>>> my_len
58
>>> my_len%4
2
>>> my_len - my_len%4
56
>>> my_range =  (my_len - my_len%4)+4
60
>> my_range//4
15

Wow we got the total number of chunks we would have i.e 15. This is exactly what i did in these few lines of code

my_len = len(a)
my_len = (my_len-my_len%4)+4
my_range = my_len//4

So range(my_range) will just mean that iterate from 0 to 14

NOTE: range(value) --> would be 0,1,2,......,value-1

Now look at this list comprehension,

[a[i*4:i*4+4] for i in range(my_range)]

Why i*4:i*4+4 ?? Because if I simply kept i:i+4 (Take the below list as example) this would happen

For i=0
[1,2,3,4,5,6,7,8,9,10,11,12]
<------->
 i:i+4 --> 0:4
For i=1
[1,2,3,4,5,6,7,8,9,10,11,12]
   <----->
    i:i+4 --> 1:5

You see what's the problem? However for [i*4:i*4+4]

For i=0
[1,2,3,4,5,6,7,8,9,10,11,12]
<------->
 i*4:i*4+4 --> 0:4
For i=1
[1,2,3,4,5,6,7,8,9,10,11,12]
         <----->
         i*4:i*4+4 --> 4:(4+4) --> 4:8

Now this is what you want. Hope this cleared you up.