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I have a file with lines of DNA in a file called 'DNASeq.txt'. I need a code to read each line and split each line at random places (inserting spaces) throughout the line. Each line needs to be split at different places.

EX: I have:
AAACCCHTHTHDAFHDSAFJANFAJDSNFADKFAFJ
And I need something like this:
AAA ADSF DFAFDDSAF ADF ADSF AFD AFAD

I have tried (!!!very new to python!!):

import random

for x in range(10):
 print(random.randint(50,250))

but that prints me random numbers. Is there some way to get a random number generated as like a variable?

You can read a file line wise, write each line character-wise in a new file and insert spaces randomly:

Create demo file without spaces:

with open("t.txt","w") as f:
 f.write("""ASDFSFDGHJEQWRJIJG
ASDFJSDGFIJ
SADFJSDFJJDSFJIDFJGIJSRGJSDJFIDJFG
SDFJGIKDSFGOROHPTLPASDMKFGDOKRAMGO""")

Read and rewrite demo file:

import random
max_no_space = 9 # if max sequence length without space
no_space = 0
with open("t.txt","r") as f, open("n.txt","w") as w: 
 for line in f:
 for c in line:
 w.write(c)
 if random.randint(1,6) == 1 or no_space >= max_no_space:
 w.write(" ")
 no_space = 0
 else:
 no_space += 1
with open("n.txt") as k:
 print(k.read())

Output:

ASDF SFD GHJEQWRJIJG 
A SDFJ SDG FIJ
SADFJSD FJ JDSFJIDFJG I JSRGJSDJ FIDJFG 

The pattern of spaces is random. You can influence it by settin max_no_spaces or remove the randomness to split after max_no_spaces all the time

Edit:

This way of writing 1 character at a time if you need to read 200+ en block is not very economic, you can do it with the same code like so:

with open("t.txt","w") as f:
 f.write("""ASDFSFDGHJEQWRJIJSADFJSDFJJDSFJIDFJGIJSRGJSDJFIDJFGG
ASDFJSDGFIJSADFJSDFJJDSFJIDFJGIJSRGJSDJFIDJFGSADFJSDFJJDSFJIDFJGIJK
SADFJSDFJJDSFJIDFJGIJSRGJSDJFIDJFGSADFJSDFJJDSFJIDFJGIJSRGJSDJFIDJF
SDFJGIKDSFGOROHPTLPASDMKFGDOKRAMGSADFJSDFJJDSFJIDFJGIJSRGJSDJFIDJFG""")


import random
min_no_space = 10
max_no_space = 20 # if max sequence length without space
no_space = 0
with open("t.txt","r") as f, open("n.txt","w") as w: 
 for line in f:
 for c in line:
 w.write(c)
 if no_space > min_no_space:
 if random.randint(1,6) == 1 or no_space >= max_no_space:
 w.write(" ")
 no_space = 0
 else:
 no_space += 1
with open("n.txt") as k:
 print(k.read())

Output:

ASDFSFDGHJEQ WRJIJSADFJSDF JJDSFJIDFJGIJ SRGJSDJFIDJFGG
 ASDFJSDGFIJSA DFJSDFJJDSFJIDF JGIJSRGJSDJFIDJ FGSADFJSDFJJ DSFJIDFJGIJK
SADFJ SDFJJDSFJIDFJG IJSRGJSDJFIDJ FGSADFJSDFJJDS FJIDFJGIJSRG JSDJFIDJF
SDFJG IKDSFGOROHPTLPASDMKFGD OKRAMGSADFJSDF JJDSFJIDFJGI JSRGJSDJFIDJFG

If you want to split your DNA fixed amount of times (10 in my example) here's what you could try:

import random

DNA = 'AAACCCHTHTHDAFHDSAFJANFAJDSNFADKFAFJ'
splitted_DNA = ''

for split_idx in sorted(random.sample(range(len(DNA)), 10)):
 splitted_DNA += DNA[len(splitted_DNA)-splitted_DNA.count(' ') :split_idx] + ' '
splitted_DNA += DNA[split_idx:]

print(splitted_DNA) # -> AAACCCHT HTH D AF HD SA F JANFAJDSNFA DK FAFJ

import random

with open('source', 'r') as in_file:
 with open('dest', 'w') as out_file:
 for line in in_file:
 newLine = ''.join(map(lambda x:x+' '*random.randint(0,1), line)).strip() + 'n'
 out_file.write(newLine)

Since you mentioned being new, I'll try to explain

• I'm writing the new sequences to another file for precaution. It's
  not safe to write to the file you are reading from.




• The with constructor is so that you don't need to explicitly close
  the file you opened.




• Files can be read line by line using for loop.




• ''.join() converts a list to a string.




• map() applies a function to every element of a list and returns the
  results as a new list.




• lambda is how you define a function without naming it. lambda x:
2*x doubles the number you feed it.




• x + ' ' * 3 adds 3 spaces after x. random.randint(0, 1) returns
  either 1 or 0. So I'm randomly selecting if I'll add a space after
  each character or not. If the random.randint() returns 0, 0 spaces are added.

You can toss a coin after each character whether to add space there or not.
This function takes string as input and returns output with space inserted at random places.

def insert_random_spaces(str):
 from random import randint
 output_string = "".join([x+randint(0,1)*" " for x in str])
 return output_string