# Harvard:Biophysics 101/2007/02/08

## Q&A

• Q1: "I keep getting indentation errors when running my python scripts - what's the deal?"
• A1: See 1, 2 for info.

## Solution to Feb 6 Assignment

• Here's my take on the Feb 6 assignment. --smd 12:28, 8 February 2007 (EST)
```#!/usr/bin/env python

from random import choice

# create a list to store our results
tally = [0 for i in range(11)]

for i in range(10000):
# generate a random 10-mer
coinflip = ''.join([choice('HT') for j in range(10)])

# tally k-mers in the 10-mer
for k in range(2,11):
Hcount = Tcount = 0

H = ''.join(['H' for n in range(k)]) # k-mer of H's
pos = coinflip.find(H,0)
while not pos == -1:
Hcount = Hcount + 1
pos = coinflip.find(H,pos+1)

T = ''.join(['T' for n in range(k)]) # k-mer of T's
pos = coinflip.find(T,0)
while not pos == -1:
Tcount = Tcount + 1
pos = coinflip.find(T,pos+1)

tally[k] = tally[k] + Hcount + Tcount

for i in range(2,11):
print '%2s: %5d' % (i, tally[i])
```
• Example output
``` 2: 45129
3: 20055
4:  8776
5:  3784
6:  1588
7:   638
8:   247
9:    81
10:    22
```