python - create and insert randomly duplicates -

this not common question want create duplicates , insert randomly in string. following example.

i have file :

applestrawberrybananacitrusorange 

and expected kind of output :

truspplestrawbeapplertrusrybananacitrusorangepple 

in case program randomly select substring of length '4' : 'pple' , 'trus' , duplicates him 'twice(2)' before insertion.

i think run program using fonction copy copy.copy() , copy.insert() don't know how use randomly.

for moment;i write part of code read , write , else:

import copy    chain='*'  contain = ''    file= raw_input ('filename:')      x = open(file,'r')    line in x:  		  if not(chain in line):  	contain+=line  	e=copy.copy(contain[4:8])  	f=copy.copy(contain[8:12])      y = open('copi','w')      y.write(contain)  y.write(f)        x.close()

result:

applestrawberrybananacitrusorange awbe 

as can see; doesn't work want. :(

thanks help

not sure if understand trying do.

you'll need library random selection:

import random 

now here input string:

s = "applestrawberrybananacitrusorange" print s 

you can use random.randint select random position , extract 4-character word:

i = random.randint(0, len(s) - 4) w = s[i:i+4] print w 

finally, can select 2 more random positions , insert word via string concatenation:

for j in range(2):     = random.randint(0, len(s) - 4)     s = s[:i] + w + s[i:] print s 

output:

applestrawberrybananacitrusorange yban apybanplesybantrawberrybananacitrusorange