TChan/Notebook/2007-2-8

BP 101: Script 1

Assignment:

• Write a python script that generates 10,000 strings of 10 random coinflips (H or T) and outputs the tally of continguous (overlapping) stretches of 2, 3, 4, 5, 6, 7, 8, 9, and 10 H's or T's in that set of 10,000 10-mers.
• Post your code to your personal calendar entry for Feb 8, along with the output when it is run.
```#!/usr/bin/python

import sys
import random

contiguous_Hs = [0,0,0,0,0,0,0,0,0,0]
contiguous_Ts = [0,0,0,0,0,0,0,0,0,0]

max_repeat = 10

for i in range(10000):
flip_unit = ''
for j in range(10):
flip_unit = flip_unit + H_or_T
for k in range(max_repeat):
substr_H = ''.join(['H' for n in range(k+1)])
substr_T = ''.join(['T' for p in range(k+1)])
count_H = 0
count_T = 0
pos_H = flip_unit.find(substr_H,0)
pos_T = flip_unit.find(substr_T,0)
while not pos_H == -1:
count_H = count_H + 1
pos_H = flip_unit.find(substr_H,pos_H+1)
while not pos_T == -1:
count_T = count_T + 1
pos_T = flip_unit.find(substr_T,pos_T+1)
contiguous_Hs[(len(substr_H)-1)] = contiguous_Hs[(len(substr_H)-1)] + count_H
contiguous_Ts[(len(substr_T)-1)] = contiguous_Ts[(len(substr_T)-1)] + count_T

print 'Contiguous Hs:'
for a in range(len(contiguous_Hs)-1):
num_of_Hs = ('H'*a) + 'H'
print '%12s %d' % (num_of_Hs, contiguous_Hs[len(num_of_Hs)])

print '\n'

print 'Contiguous Ts:'
for b in range(len(contiguous_Ts)-1):
num_of_Ts = ('T'*b) + 'T'
print  '%12s %d' % (num_of_Ts, contiguous_Ts[len(num_of_Ts)])

```

```Contiguous Hs:
H 22780
HH 10285
HHH 4629
HHHH 2047
HHHHH 839
HHHHHH 343
HHHHHHH 133
HHHHHHHH 45
HHHHHHHHH 11

Contiguous Ts:
T 22314
TT 9909
TTT 4369
TTTT 1873
TTTTT 771
TTTTTT 303
TTTTTTT 110
TTTTTTTT 38
TTTTTTTTT 5
```