Harvard:Biophysics 101/Notebook:ZS/2007-2-8

Assignment 2

link to assignment

Code

#!/usr/bin/env python

#Assignment 2, Zachary Sun (zsun@fas)

from random import *
hcount = 0
tcount = 0
string = []
y = []
w = []
u = ''
v = ''

for t in range(10): # creates a list of repetitive T's
    u = u + "T" 
    y.append(u)

for t in range(10): # creates a list of repetitive T's
    v = v + "H" 
    w.append(v)
    
for i in range(10000): # create the random coin tosses and strings
    flip = ''
    for z in range(10):
        if random() < 0.5:
            flip = flip + "H"
            hcount = hcount + 1
        else:
            flip = flip + "T"
            tcount = tcount + 1
    string.append(flip)

for z in y: # counting continuous stretches of T
    countStretch = 0
    for i in range(len(string)):
        countStretch = countStretch + string[i].count(z)       
    print z,':',countStretch

print '\n'

for z in w: # counting continuous stretches of H
    countStretch = 0
    for i in range(len(string)):
        countStretch = countStretch + string[i].count(z)       
    print z,':',countStretch

Output

T : 49899
TT : 15491
TTT : 6093
TTTT : 2581
TTTTT : 1076
TTTTTT : 471
TTTTTTT : 194
TTTTTTTT : 73
TTTTTTTTT : 29
TTTTTTTTTT : 7


H : 50101
HH : 15652
HHH : 6152
HHHH : 2619
HHHHH : 1131
HHHHHH : 486
HHHHHHH : 183
HHHHHHHH : 76
HHHHHHHHH : 29
HHHHHHHHHH : 5