# Harvard:Biophysics 101/2007/Notebook:Resmi Charalel/2007-2-8

## Script

``` #!/usr/bin/env python

from random import *

mx=10
countH=[0,0,0,0,0,0,0,0,0]
countT=[0,0,0,0,0,0,0,0,0]

#Generation of list of 10,000 strings of 10 random coinflips and tally of stretches of H's and T's
for x in range(10000):
s=[]
for i in range(mx):
random = choice(range(0,2,1))

if random==0:
s.append('H')

if random==1:
s.append('T')
substr=.join(s)

for i in range(9):
substH = .join(['H' for n in range(i+2)])
pos = substr.find(substH,0)

while not pos == -1:
countH[i] = countH[i] + 1
pos = substr.find(substH,pos+1)

for i in range(9):
substT = .join(['T' for n in range(i+2)])

pos = substr.find(substT,0)
while not pos == -1:
countT[i] = countT[i] + 1
pos = substr.find(substT,pos+1)

print "10,000 strings of 10 random coinflips were generated.  The following tallies of H's and T's were recorded."
print "Occurence(s) of HH:", countH[0]
print "Occurence(s) of HHH:", countH[1]
print "Occurence(s) of HHHH:", countH[2]
print "Occurence(s) of HHHHH:", countH[3]
print "Occurence(s) of HHHHHH:", countH[4]
print "Occurence(s) of HHHHHHH:", countH[5]
print "Occurence(s) of HHHHHHHH:", countH[6]
print "Occurence(s) of HHHHHHHHH:", countH[7]
print "Occurence(s) of HHHHHHHHHH:", countH[8]
print "Occurence(s) of TT:", countT[0]
print "Occurence(s) of TTT:", countT[1]
print "Occurence(s) of TTTT:", countT[2]
print "Occurence(s) of TTTTT:", countT[3]
print "Occurence(s) of TTTTTT:", countT[4]
print "Occurence(s) of TTTTTTT:", countT[5]
print "Occurence(s) of TTTTTTTT:", countT[6]
print "Occurence(s) of TTTTTTTTT:", countT[7]
print "Occurence(s) of TTTTTTTTTT:", countT[8]
```

## Output

``` 10,000 strings of 10 random coinflips were generated.  The following tallies of H's and T's were recorded.
Occurence(s) of HH: 22483
Occurence(s) of HHH: 9995
Occurence(s) of HHHH: 4404
Occurence(s) of HHHHH: 1894
Occurence(s) of HHHHHH: 818
Occurence(s) of HHHHHHH: 342
Occurence(s) of HHHHHHHH: 136
Occurence(s) of HHHHHHHHH: 48
Occurence(s) of HHHHHHHHHH: 14
Occurence(s) of TT: 22591
Occurence(s) of TTT: 10146
Occurence(s) of TTTT: 4492
Occurence(s) of TTTTT: 1905
Occurence(s) of TTTTTT: 771
Occurence(s) of TTTTTTT: 291
Occurence(s) of TTTTTTTT: 108
Occurence(s) of TTTTTTTTT: 36
Occurence(s) of TTTTTTTTTT: 8
```