Python examples

math formulas
assignment statements
lists and slices
  len(L), L.append(s), L.extend([1,2]) ...
        tuples are immutable lists  x = (1,2,3)
Booleans: False and True
2 > 3
L[1] == 2
2 in L
defining functions (factorial)
Manipulating directories and files:
os and os.path modules

import os
os.getcwd()  = returns string which names current dir
os.chdir("C:/") or os.chdir("C:\\")
myfile = open("....")
s = myfile.readline()
ss = myfile.readlines()
***********************************************
Updating lists L = [1,2,3,5]
L[:1] = [3,4]

>>> L

[3, 4, 2, 3, 5]

>>> L[0] = [7,8]

>>> L

[[7, 8], 4, 2, 3, 5]


>>> 
DICTIONARIES
d = {}

d[1] = "sal"
d["never"] = "val"
d[(2,2)] = "hal"
d.keys()
d.values()
d.items()
When your program opens the percept file, 
use:
pfile = open('./percepts.txt') 
Two approaches to reading data structures from files:

[Yes , Happy] --> using r = pfile.readline() and then parsing it

["Yes" , "Happy"] --> using p = eval(pfile.readline())

Please use the SECOND approach this time, as shown in the assignment.

Classes and OO programs: next time

example programs: factorial.py, count.py, vacuum.py and match.py