Python 2.5.2 (r252:60911, Feb 22 2008, 07:57:53) 
[GCC 4.0.1 (Apple Computer, Inc. build 5363)]
Type "help", "copyright", "credits" or "license" for more information.
>>> # and - true if both are true; false, otherwise
>>> x = 5
>>> y = 44
>>> x == 5 and y == 44
True
>>> x == 5 and y == 440
False
>>> x == 50 and y == 44
False
>>> #or
>>> 
>>> tall = True
>>> short = False
>>> woman = True
>>> man = False
>>> tall or short
True
>>> man or woman
True
>>> tall or woman
True
>>> short or man # only if both are False is the result false
False
>>> # we can combine these as many times as we want
>>> (False or True) and (False or True)
True
>>> (False and False) or (False or True)
True
>>> #Boolean is stroed internally as 0 and True as 1, with interesting effects
>>> if 9.23345:
... 	print 'yes'
... 
yes
>>> # for fun what does the following do?  NOTE: Terrible style!
>>> num = 6
>>> if num == 10 or 20 or 30:
... 	print 'yeah'
... else:
... 	print 'no way'
... 
yeah
>>> # num is 6; 6 is not zero, so True
>>> # 10 or 20 or 30 is True or True or True
>>> # So, the test is True == True, which is True
>>> # But don't program like this!
>>> 
>>> #lazy evaluation:  python does not evaluate something it doesn't need to
>>> # x and y : if x is False, we know the answer is False.  No need to evaluate y
>>> # x or y:  if x is True, we know the answer is True.  No need to evaluate y
>>> # To see this, note that 4/0 would give an error
>>> 4/0
Traceback (most recent call last):
  File "<string>", line 1, in <string>
ZeroDivisionError: integer division or modulo by zero
>>> True or 4/0
True
>>> # The example above shows Python did not evaluation 4/0
>>> 4/0 or True
Traceback (most recent call last):
  File "<string>", line 1, in <string>
ZeroDivisionError: integer division or modulo by zero
>>> # Now, let's move onto strings
>>> 'cs401'
'cs401'
>>> "cs401" # use double or single quotes
'cs401'
>>> "cs401' # but you can't mix them
Traceback (most recent call last):
  File "<string>", line 1, in <string>
EOL while scanning single-quoted string: <string>, line 1, pos 32
>>> # + concatenates 2 strings - glues them together
>>> 'cs' + '0007'
'cs0007'
>>> 'cs' + '401'
'cs401'
>>> 'cs' + 401 # error!  the operands need to be the same type
Traceback (most recent call last):
  File "<string>", line 1, in <string>
TypeError: cannot concatenate 'str' and 'int' objects
>>> 'cs' + str(401) # change the int to a str, and things are fine
'cs401'
>>> int(25.4)
25
>>> float('45') # python will make sense of this if it can.  
45.0
>>> # It first went from str to int; then from int to float.
>>> #  * is also defined for strings
>>> "Tigers are " + "fun" * 4
'Tigers are funfunfunfun'
>>> # another type of boolean expression: uses the 'in' keyword
>>> 's' in 'pragmatics'
True
>>> #True, because the char 's' is in the string 'pragmatics'
>>> # Now, write the code in [string_funs.py]
>>>