# PythonPrograms.txt
# anne.dawson@gmail.com
# Last updated: Thursday 19th October 2006, 8:03 PT
# Please Note: lines starting with a # are comments
# and are ignored by
# the Python interpreter
# http://www.annedawson.com/PythonComments.txt
# Any of these example programs can be run by
# directly copying the desired program and pasting
# the code to a Python editor such as IDLE...
# http://www.annedawson.com/Python_Program_Run.htm
# The first Python program (01-01.py) has only
# one executable line:
# print "Hello World!"
# and one comment line
# A selection of these example programs are used in courses
# CSCI100, CSCI120, CSCI165 and BUSI237
#01-01.py
print "Hello World!"
#01-02.py
thetext = raw_input("Enter some text ")
print "This is what you entered:"
print thetext
#01-03.py
# Note that \n within quote marks forces a new line to be printed
thetext = raw_input("Enter some text\n")
print "This is what you entered:"
print thetext
#01-04.py
prompt = "Enter a some text "
thetext = raw_input(prompt)
print "This is what you entered:"
print thetext
#02-01.py
total = 0.0
number1=float(raw_input("Enter the first number: "))
total = total + number1
number2=float(raw_input("Enter the second number: "))
total = total + number2
number3=float(raw_input("Enter the third number: "))
total = total + number3
average = total / 3
print "The average is " + str(average)
#02-02.py
number1=float(raw_input("Enter the first number: "))
number2=float(raw_input("Enter the second number: "))
number3=float(raw_input("Enter the third number: "))
total = number1 + number2 + number3
average = total / 3
print "The average is " + str(average)
#02-03.py
total = 0.0
count = 0
while count < 3:
number=float(raw_input("Enter a number: "))
count = count + 1
total = total + number
average = total / 3
print "The average is " + str(average)
#03-01.py
sum = 10
#03-02.py
sum = 10
print sum
#03-03.py
sum = 10
print sum
print type (sum)
#03-04.py
print 2 + 4
print 6 - 4
print 6 * 3
print 6 / 3
print 6 % 3
print 6 // 3 # floor division: always truncates fractional remainders
print -5
print 3**2 # three to the power of 2
#03-05.py
print 2.0 + 4.0
print 6.0 - 4.0
print 6.0 * 3.0
print 6.0 / 3.0
print 6.0 % 3.0
print 6.0 // 3.0 # floor division: always truncates fractional remainders
print -5.0
print 3.0**2.0 # three to the power of 2
#03-06.py
# mixing data types in expressions
# mixed type expressions are "converted up"
# converted up means to take the data type with the greater storage
# float has greater storage (8 bytes) than a regular int (4 bytes)
print 2 + 4.0
print 6 - 4.0
print 6 * 3.0
print 6 / 3.0
print 6 % 3.0
print 6 // 3.0 # floor division: always truncates fractional remainders
print -5.0
print 3**2.0 # three to the power of 2
#03-07.py
# these are Boolean expressions which result in a value of
# true or false
# Note that Python stores true as integer 1, and false as integer 0
# but outputs 'true' or 'false' from print statements
print 7 > 10
print 4 < 16
print 4 == 4
print 4 <= 4
print 4 >= 4
print 4 != 4
print 4 <> 4
#03-08.py
# these are string objects
print "Hello out there"
print 'Hello'
print "Where's the spam?"
print 'x'
#03-09.py
# these are string assignments
a = "Hello out there"
print a
b = 'Hello'
print b
c = "Where's the spam?"
print c
d = 'x'
print d
#03-10.py
a = 'Hello out there'
b = "Where's the spam?"
c = a + b
print c
#03-11.py
a = 'Hello out there'
b = "Where's the spam?"
c = a + b
print c
#d = c + 10
# you cannot concatenate a string and an integer
# you must convert the integer to a string first:
d = c + str(10)
print d
#03-12.py
a = "10"
b = '99'
c = a + b
print c
print type(c)
c = int(c)
print c
print type(c)
# File: 04-01.py
# Purpose: Creating a string object
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 12:43 PT
number1 = raw_input("Enter first number:\n")
print number1, type(number1)
# File: 04-02.py
# Purpose: Converting one data type to another
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 12:46 PT
number1 = raw_input("Enter first number:\n")
print number1, type(number1)
number1 = int(number1)
print number1, type(number1)
# File: 04-03.py
# Purpose: Displaying an object's memory location
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 12:48 PT
number1 = raw_input("Enter first number:\n")
print number1, type(number1), id(number1)
number1 = int(number1)
print number1, type(number1), id(number1)
# File: 04-04.py
# Purpose: Examples of use of arithmetic operators
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 13:09 PT
print 2 + 4
print 6 - 4
print 6 * 3
print 6 / 3
print 6 % 3
print 6 // 3 # floor (integer) division: always truncates fractional remainders
print -5
print 3**2 # three to the power of 2
# File: 04-05.py
# Purpose: Examples of use of arithmetic operators with float values
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 13:10 PT
print 2.0 + 4.0
print 6.0 - 4.0
print 6.0 * 3.0
print 6.0 / 3.0
print 6.0 % 3.0
print 6.0 // 3.0 # floor (integer) division: always truncates fractional remainders
print -5.0
print 3.0**2.0 # three to the power of 2
# File: 04-06.py
# Purpose: Examples of use of arithmetic operators
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 13:10 PT
# mixing data types in expressions
# mixed type expressions are "converted up"
# converted up means to take the data type with the greater storage
# float has greater storage (8 bytes) than a regular int (4 bytes)
print 2 + 4.0
print 6 - 4.0
print 6 * 3.0
print 6 / 3.0
print 6 % 3.0
print 6 // 3.0 # floor division: always truncates fractional remainders
print -5.0
print 3**2.0 # three to the power of 2
# File: 04-07.py
# Purpose: Examples of use of Boolean expressions
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 13:12 PT
# these are Boolean expressions which result in a value of
# true or false
# Note that Python stores true as integer 1, and false as integer 0
# but outputs 'true' or 'false' from print statements
# If you input Boolean values, you must input 1 or 0.
print 7 > 10
print 4 < 16
print 4 == 4
print 4 <= 4
print 4 >= 4
print 4 != 4
print 4 <> 4
# File: 04-08.py
# Purpose: Displaying boolean values
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 12:54 PT
number = 10
isPositive = (number > 0)
print isPositive
# File: 04-09.py
# Purpose: Combining boolean expressions with and
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 13:18 PT
age = 25
salary = 55000
print (age > 21) and (salary > 50000)
# File: 04-10.py
# Purpose: The if statement
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 13:23 PT
# The condition of the following if statement
# follows the word if, and ends with a colon (:)
# In this example, if x has a value equal to 'spam',
# then 'Hi spam' will be printed.
x = 'spam'
if x == 'spam':
print 'Hi spam'
else:
print 'not spam'
# Notice the indentation (spacing out) of this code.
# The statement(s) following the if condition (i.e. boolean expression)
# must be indented to the next tab stop. This means you must press
# the Tab button before typing the word print.
# Try removing the tab spaces and see what happens when you attempt to run.
# File: 04-11.py
# Purpose: The if statement with multiple statements
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 13:23 PT
# The condition of the following if statement
# follows the word if, and ends with a colon (:)
# In this example, if x has a value equal to 'spam',
# then 'Hi spam\n' will be printed followed by
# "Nice weather we're having"
# followed by 'Have a nice day!'
x = 'spam'
if x == 'spam':
print 'Hi spam\n'
print "Nice weather we're having"
print 'Have a nice day!'
else:
print 'not spam'
# Notice the indentation (spacing out) of this code.
# The statement(s) following the if condition (i.e. boolean expression)
# must be indented to the next tab stop. This means you must press
# the Tab button before typing the word print.
# Try removing the tab spaces and see what happens when you attempt to run.
# File: 04-12.py
# Purpose: The if statement with multiple statements
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 27th September 2004, 13:23 PT
# The condition of the following if statement
# follows the word if, and ends with a colon (:)
# In this example, if x has a value equal to 'spammy',
# then 'Hi spam\n' will be printed followed by
# "Nice weather we're having"
# followed by 'Have a nice day!'
x = 'spam'
if x == 'spammy':
print 'Hi spam\n'
print "Nice weather we're having"
print 'Have a nice day!'
else:
print 'not spam'
print 'Not having a good day?'
# Notice the indentation (spacing out) of this code.
# The statement(s) following the if condition (i.e. boolean expression)
# must be indented to the next tab stop. This means you must press
# the Tab button before typing the word print.
# Try removing the tab spaces and see what happens when you attempt to run.
# Program: 04-13.py
# Purpose: A nested if example (an if statement within another if statement)
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 4th October 2004, 13:21 PT
score = raw_input("Enter score: ")
score = int(score)
if score >= 80:
grade = 'A'
else:
if score >= 70:
grade = 'B'
else:
grade = 'C'
print "\n\nGrade is: " + grade
# Program: 04-14.py
# Purpose: A nested if example - using if/else
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 4th October 2004, 13:25 PT
score = raw_input("Enter score: ")
score = int(score)
if score >= 80:
grade = 'A'
else:
if score >= 70:
grade = 'B'
else:
if score >= 55:
grade = 'C'
else:
if score >= 50:
grade = 'Pass'
else:
grade = 'Fail'
print "\n\nGrade is: " + grade
# Program: 04-15.py
# Purpose: A nested if example - using if/elif/else
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 4th October 2004, 13:28 PT
score = raw_input("Enter score: ")
score = int(score)
if score >= 80:
grade = 'A'
elif score >= 70:
grade = 'B'
elif score >= 55:
grade = 'C'
elif score >= 50:
grade = 'Pass'
else:
grade = 'Fail'
print "\n\nGrade is: " + grade
# File: 04-16.py
# Purpose: Demo of DeMorgan's Laws:
# 1. a Not And is equivalent to an Or with two negated inputs
# 2. a Not Or is equivalent to an And with two negated inputs
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 21st March 2005, 05:53 PT
# Test data: 0 0, 0 1, 1 0, 1 1
# For ***any*** value of x and y, (not(x < 15 and y >= 3)) == (x >= 15 or y < 3)
# Common uses of De Morgan's rules are in digital circuit design
# where it is used to manipulate the types of logic gates.
# Also, computer programmers use them to change a complicated statement
# like IF ... AND (... OR ...) THEN ... into its opposite (and shorter) equivalent.
# http://en.wikipedia.org/wiki/De_Morgan%27s_law
# http://www.coquitlamcollege.com/adawson/DeMorgansLaws.htm
x = int(raw_input("Enter a value for x: "))
y = int(raw_input("Enter a value for y: "))
print (not(x < 15 and y >= 3))
print (x >= 15 or y < 3)
# File: 05-01.py
# Purpose: Examples of while loops
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 30th September 2004, 15:51 PT
# You must remember to indent the statements to be repeated.
# They must be repeated to the same level.
# Use the Tab key to indent. The space bar can be used but
# its easier (less typing) to use the space bar
# Used like this, the while loop is said to be
# 'counter-controlled'. In this program, x is acting as a counter.
x = 1
while x < 5:
print 'Hi spam'
x = x + 1
print 'done'
# File: 05-02.py
# Purpose: Examples of while loops
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 30th September 2004, 15:51 PT
# Used like this, the while loop is said to be
# 'counter-controlled'. In this program, x is acting as a counter.
# You may repeat one statement or multiple statements.
x = 1
while x < 5:
print 'Hi spam'
x = x + 1
print 'I love spam'
print 'done'
print 'gone'
# File: 05-03.py
# Purpose: Examples of while loops - the infinite loop
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 30th September 2004, 15:51 PT
# An infinite loop.
# Remember that 1 (or any value other than 0) represents true.
# Press Ctrl-C to interupt this program run.
x = 1
while x:
print 'Hi spam'
x = x + 1
print 'I love spam'
print 'Press the Ctrl key and the C key together'
print 'to interupt this program...'
print 'done'
print 'gone'
# File: 05-04.py
# Purpose: Examples of while loops - another infinite loop
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 30th September 2004, 16:00 PT
# An infinite loop.
# Remember that 1 (or any value other than 0) represents true.
# Press Ctrl-C to interupt this program run.
while 1:
print 'Anyone for spam? '
print 'Press the Ctrl key and the C key together'
print 'to interrupt this program...'
print 'done'
print 'gone'
# File: 05-05.py
# Purpose: Example: use of break to end an infinite loop
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 30th September 2004, 16:02 PT
while 1:
print 'Spam'
answer = raw_input('Press y to end this loop')
if answer == 'y':
print 'Fries with that?'
break
print 'Have a '
print 'nice day!'
# File: 05-06.py
# Purpose: Example: use of continue in a loop
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 30th September 2004, 16:07 PT
while 1:
print 'Spam'
answer = raw_input('Press y for large fries ')
if answer == 'y':
print 'Large fries with spam, mmmm, yummy '
continue
answer = raw_input('Had enough yet? ')
if answer == 'y':
break
print 'Have a '
print 'nice day!'
# File: 05-07.py
# Purpose: Example: 'sentinel-controlled' while loop
# Calculates average score of a class
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 5th October 2004, 6:31 PT
# initialization phase
totalScore = 0 # sum of scores
numberScores = 0 # number of scores entered
# processing phase
score = raw_input( "Enter score, (Enter -9 to end): " ) # get one score
score = int( score ) # convert string to an integer
while score != -9: # -9 is used as a sentinel ( a lookout or sentry value )
totalScore = totalScore + score
numberScores = numberScores + 1
score = raw_input( "Enter score, (Enter -9 to end): " )
score = int( score )
# termination phase
if numberScores != 0: # division by zero would be a run-time error
average = float( totalScore ) / numberScores
print "Class average is", average
else:
print "No scores were entered"
# File: 05-08.py
# Purpose: Example: the counter-controlled for loop
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 5th October 2004, 6:53 PT
for c in range (10):
print c
# Note: range (10) is 0 through 9
# File: 05-09.py
# Purpose: Example: the counter-controlled for loop
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 5th October 2004, 6:58 PT
for c in range (5,10):
print c
# Note: range (5,10) is 5 through 9
# File: 05-10.py
# Purpose: Example: 'continue' with the for loop
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 5th October 2004, 6:58 PT
for c in range (1,6):
if c == 3:
continue
print c
# File: 05-11.py
# Purpose: Example: 'break' with the for loop
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 5th October 2004, 7:05 PT
for c in range (1,6):
if c == 3:
break
print c
# File: 05-12.py
# Purpose: Example: outputting strings and numbers
# in a single print statement
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 5th October 2004, 7:21 PT
d = 10
c = 75
print 'Total is: ', d, 'dollars and', c, ' cents'
# File: 05-13.py
# Purpose: Example: outputting strings and numbers
# in a single print statement
# using string formatting.
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 5th October 2004, 7:35 PT
x = 20
y = 75
print 'The sum of %d and %d is %d' % (x, y, x + y)
x = 20.512
y = 15.269
print 'The sum of %f and %f is %f' % (x, y, x + y)
x = 20.512
y = 15.269
print 'The sum of %0.2f and %0.2f is %0.2f' % (x, y, x + y)
# File: 05-14.py
# Purpose: Example: how to repeat a program at the user's request
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 19th October 2006, 7:58 PT
print "This is the start of the program"
answer = 'y'
while (answer == 'y' or answer == 'Y'):
print "This is a statement from within the while loop"
print "This is another statement from within the while loop"
answer = raw_input("Do you want to run this program again? y/n")
print "Goodbye!"
# File: 06-01.py
# Purpose: Example: using the built-in square root function math.sqrt
# To use any math function, you have to include the statement:
# import math
# in your program - usually at the top, but can be anywhere.
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Friday 6th October 2006, 8:54 PT
import math
print math.sqrt(16)
print math.sqrt(16.5)
x = 144
print math.sqrt(x)
# File: 06-02.py
# Purpose: Example: using the dir function to list out the names
# of available functions in the math module
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 11th October 2004, 7:59 PT
import math
print math
print dir(math)
# File: 06-03.py
# Purpose: Example: using a programmer-defined function
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 11th October 2004, 8:19 PT
# start of function definition
def cube( y ):
return y * y * y
# end of function definition
# prints the cube of numbers 1 to 5
for x in range(1,6):
print cube(x)
# the last value of x is 5
print "last value of x is:",x
# File: 06-04.py
# Purpose: Example: using two programmer-defined functions
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 11th October 2004, 8:45 PT
def cube( y ):
return y * y * y
def doubleIt ( z ):
return 2 * z
print "1 to 5 cubed"
for x in range(1,6):
print cube(x),
print
print
print "1 to 5 doubled"
for x in range(1,6):
print doubleIt(x),
# File: myFunctions.py
# Purpose: two programmer-defined functions
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 11th October 2004, 8:57 PT
def cube( y ):
return y * y * y
def doubleIt ( z ):
return 2 * z
# File: 06-05.py
# Purpose: Example: importing programmer-defined functions
# from its own module file
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 11th October 2004, 8:56 PT
# IMPORTANT: myFunctions.py should be in the same folder as this file
import myFunctions
print "1 to 5 cubed"
for x in range(1,6):
print myFunctions.cube(x),
print
print
print "1 to 5 doubled"
for x in range(1,6):
print myFunctions.doubleIt(x),
# File: 06-06.py
# Purpose: Example: function with no return statement
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 12th October 2004, 6:30 PT
def times(x):
for i in range(1,11):
print "%d x %d = %d" % (i, x, i * x)
print "This is the 1 times tables:"
times(1)
print "This is the 2 times tables:"
times(2)
# File: 06-07.py
# Purpose: Example: a function with two return statements
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 12th October 2004, 6:37 PT
def division(x,y):
if (y == 0):
print "division by zero not allowed"
return
else:
" returning %f divided by %f " % (x, y)
return x / y
print " 5.0 / 2 returns:"
result = division( 5.0 , 2 )
print result
print " 5.0 / 0 returns:"
result = division( 5.0 , 0 )
print result
# File: 06-08.py
# Purpose: Example: a function with no arguments
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 12th October 2004, 7:18 PT
def greeting():
print "Hello out there!"
greeting()
greeting()
greeting()
# File: 06-09.py
# Purpose: Example: a program with a Boolean function
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 12th October 2004, 7:21 PT
def isPositive(x):
if (x >= 0):
return 1 # 1 is true
else:
return 0 # 0 is false
x = float(raw_input("Enter a positive or negative number: "))
result = isPositive(x)
print result
print isPositive(x)
# File: 06-10.py
# Purpose: Example: a polymorphic function
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 12th October 2004, 7:34 PT
def doubleIt(x):
return (2 * x)
y = 3
print doubleIt(y)
z = "Spam "
print doubleIt(z)
# This program works because the * operator can be used with
# numbers and with strings. This is an example of Polymorphism.
# Poly means "many" and morph means "form"
# Polymorphism : the meaning of the operations depends on the objects
# being operated on. The * operator is said to be "overloaded"
# An overloaded operator behaves differently depending on
# the type of its operands.
# File: 07-01.py
# Purpose: Example: creating and using a Python list
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 25th October 2004, 8:02 PT
result = [0,0,0,0,0,0,0,0]
print result
result[0] = 75
result[1] = 90
result[4] = 72
print result
print result[0]
print result[1]
print result[2]
print result[3]
print result[4]
print result[5]
print result[6]
print result[7]
# File: 07-02.py
# Purpose: Example: creating and printing an empty list
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 25th October 2004, 8:15 PT
list1 = []
print list1
# the following statement would generate an error
#print list1[0]
# File: 07-03.py
# Purpose: Example: appending to an empty list
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 25th October 2004, 8:17 PT
list1 = []
print list1
list1.append(67)
print list1[0]
list1.append("spam")
print list1
print list1[0]
print list1[1]
# the following statement would generate an out-of-range error
#print list1[2]
# File: 07-04.py
# Purpose: Example: a list of lists
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 25th October 2004, 8:22 PT
list1 = [1,2,3]
print list1
list2 = [4,5,6]
print list2
list3=[list1,list2]
print list3
print list3[0]
print list3[1]
# File: 07-05.py
# Purpose: Example: accessing the last item in a list
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 25th October 2004, 8:27 PT
list1 = [1,2,3,6,7,8,9,10]
print list1
print list1[0]
print list1[1]
print list1[-1]
print list1[-2]
# File: 07-06.py
# Purpose: Example: deleting items from a list
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 25th October 2004, 8:28 PT
list1 = [1,2,3,4,5,6,7,8,9,10]
print list1
del list1[0]
del list1[-1]
print list1
# File: 07-07.py
# Purpose: Example: repeating lists
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 4th November 2004, 6:37 PT
list1 = [1,2,3]
print list1
print list1 * 3
print list1
list1 = list1 * 2
print list1
# File: 07-08.py
# Purpose: Example: concatenating lists
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 4th November 2004, 6:55 PT
list1 = [1,2,3]
print list1
list2 = [4,5,6]
print list2
list1 = list1 + list2
print list1
list1 = list1 + list1
print list1
# File: 07-09.py
# Purpose: Example: ist indexing
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 4th November 2004, 7:07 PT
list1 = ["Anne", "Dawson", 666]
print list1[0], list1[2]
# File: 07-10.py
# Purpose: Example: list indexing
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 4th November 2004, 7:08 PT
list1 = [2,4,6,8,10,12,14,16,18,20]
print list1[0:1],list1[5:7]
# File: 07-11.py
# Purpose: Example: finding the length of a list
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 4th November 2004, 7:20 PT
list1 = ["Anne","was",'here','testing',1,2,3]
list2 = [1,2,3,4]
list3 = []
print len(list1),
print len(list2),
print len(list3)
# File: 07-12.py
# Purpose: Example: list iteration
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 4th November 2004, 7:26 PT
list = [1,2,3,"Spam",4,5]
for i in list:
print i,
# File: 07-13.py
# Purpose: Example: list membership
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 4th November 2004, 7:28 PT
list = [1,2,3,"Spam",4,5]
print "Spam" in list
# File: 07-14.py
# Purpose: Example: a selection of list methods
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 4th November 2004, 7:42 PT
list = ["B","C","A"]
print list
list.extend(["X","Y"]) # extends the list
print list
list.pop() # removes last item from the list
print list
list.pop()
print list
list.reverse() # reverses the order of the items in the list
print list
list.append("S")
print list
list.sort() # sorts the list into ascending order
print list
list.reverse() # reverses the order of the items in the list
print list
# File: 08-01.py
# Purpose: Example: strings
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Saturday 30th October 2004, 16:14 PT
print 'Anne was here'
print "9396633"
# Note that you can print a string over several lines
# if you contain it within triple quotes marks:
print '''Anne was here
on Saturday
30th October 2004'''
# File: 08-02.py
# Purpose: Example: using an apostrophe within a string
# and using double quote marks within a string
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Saturday 30th October 2004, 16:14 PT
print "This is Anne's spam"
print "This is Anne's spam and these are Jake's eggs"
# You can also print a " within a string enclosed in single quotes:
print 'Here is a double quote ", and "more"'
# File: 08-03.py
# Purpose: Example: multiplying numbers and
# multiplying strings
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Saturday 30th October 2004, 16:38 PT
print 3 * 4
print 30 * 4
print "3" * 4
print "30" * 4
# File: 08-04.py
# Purpose: Example: string concatenation
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Saturday 30th October 2004, 16:51 PT
print "Anne " + "was " + ("here " * 3)
# File: 08-05.py
# Purpose: Example: string indexing
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 1st November 2004, 7:01 PT
s1 = "Anne Dawson"
print s1[0],s1[5]
# File: 08-06.py
# Purpose: Example: string slicing
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 1st November 2004, 7:07 PT
s1 = "Anne Dawson"
print s1[0:1],s1[5:7]
print s1[6:9]
# File: 08-07.py
# Purpose: Example: finding the length of a string
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 1st November 2004, 7:10 PT
s1 = "Anne"
s2 = "Dawson"
s3 = ""
print len(s1),
print len(s2),
print len(s3)
# File: 08-08.py
# Purpose: Example: the %s string formatting code
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 1st November 2004, 8:00 PT
print 'Python is a %s language.' % 'great'
# File: 08-09.py
# Purpose: Example: finding a string within a string
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 1st November 2004, 8:11 PT
s1 = 'spamandeggs'
x = s1.find('and')
print x
# File: 08-10.py
# Purpose: Example: finding a string within a string
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 1st November 2004, 8:34 PT
s1 = 'spam and eggs'
s1.replace('and','without')
print s1
# the above shows that strings are immutable (cannot change)
s2 = s1.replace('and','without')
print s2
# File: 08-11.py
# Purpose: Example: escape sequences within a string
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 2nd November 2004, 8:29 PT
s = 'one\ntwo\tthree'
print s
# File: 08-12.py
# Purpose: Example: an escape sequence counts as one character
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Tuesday 2nd November 2004, 8:31 PT
s = 'one\ntwo\tthree'
print s
print len(s)
# File: 08-13.py
# Purpose: Example: iteration and membership with strings
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Wednesday 3rd November 2004, 7:35 PT
s = 'Anne was here'
for c in s:
print c,
print 'w' in s,
print ' ' in s,
print 'x' in s
# 08-14.py
# Anne Dawson
# Sunday 20th March 2005, 04:44 PT
# Demonstration of printing Unicode characters
# For explanation, see:
# http://www.network-theory.co.uk/docs/pytut/tut_17.html
# For character charts go to:
# http://www.unicode.org/charts/
# http://www.unicode.org/charts/PDF/U2580.pdf (Block Elements)
# \u2588 is a Full Block which can be used to build up a black square
str1 = u'Hello\u2588out there' # solid black block within text
print str1
str1 = u'\u2588\u2588' #two full block characters
print str1
print
print
print "two lines of two full blocks"
print str1
print str1
print
print
# Note: a space is \u0020
print 'two lines of two full blocks, two spaces, two full blocks:'
str1 = u'\u2588\u2588\u2588\u2588\u0020\u0020\u0020\u0020\u2588\u2588\u2588\u2588'
print str1
print str1
print
print
print 'two lines of two full blocks, the number 17 and two full blocks:'
str1 = u'\u2588\u2588\u2588\u2588\u0020\u0020' + '17' + u'\u2588\u2588\u2588\u2588'
print str1
str1 = u'\u2588\u2588\u2588\u2588\u0020\u0020\u0020\u0020\u2588\u2588\u2588\u2588'
print str1
# File: 09-01.py
# Purpose: Example: a program which uses a file
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 4th November 2004, 8:37 PT
file1 = open('C:\\temp\\file1.txt','r')
# the line above opens C:\temp\file1.txt for reading
string = file1.readline()
print string
# File: 09-02.py
# Purpose: Example: a program which uses a file
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 7th March 2005, 10:38 PT
file1 = open("C:\\temp\\tester2.txt","w")
print file1 # prints out details about the file
file1.write("Today is Monday\n")
file1.write("Tomorrow is Tuesday")
file1.close()
# File: 09-03.py
# Purpose: Example: a program which uses a file
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 7th March 2005, 10:56 PT
file2 = open("C:\\temp\\tester2.txt","r")
print file2 # prints out details about the file
string1 = file2.read()
print string1
file2.close()
file2 = open("C:\\temp\\tester2.txt","r")
string1 = file2.read(5)
print string1
string1 = file2.read(5)
print string1
string1 = file2.read(5)
print string1
file2.close()
# File: 09-04.py
# Purpose: Example: a program which uses a file
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 7th March 2005, 11:31 PT
def copyFile(oldFile, newFile):
f1 = open(oldFile, "r")
f2 = open(newFile, "w")
while 1:
text = f1.read(50)
if text == "":
break
f2.write(text)
f1.close()
f2.close()
return
filecopy = "C:\\temp\\tester2copy.txt" #this file will be created
fileold = "C:\\temp\\tester2.txt" # existing file
copyFile(fileold, filecopy)
# File: 09-05.py
# Purpose: Example: a program which uses a file
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Monday 7th March 2005, 11:31 PT
filename = raw_input('Enter a file name: ')
try:
f = open (filename, "r")
except:
print 'There is no file named', filename
# File: 10-01.py
# Purpose: Example: sequential search of a list
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 11th November 2004, 14:05 PT
list1 = [11,27,36,44,51,22,65,1,78]
numbertofind = int(raw_input("Enter a number\n"))
found = 0
for i in list1:
if numbertofind == i:
print numbertofind, " at index: ",list1.index(numbertofind)
found = 1
if found == 0:
print "Number not found"
# File: bubblesort.py
# Purpose: Example: a program which demonstrates a bubble sort on
# a list of 10 random integers
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Sunday 14th November 2004, 9:17 PT
import random
# define the bubble sort function
def sort(values):
length = len(values)
for time in range(0, length-1):
for position in range(0, (length-time-1)):
if values[position] > values[position+1]:
temp = values[position]
values[position] = values[position+1]
values[position+1] = temp
# generate a list of ten random numbers
numbers = []
number = 0
while number < 10:
value = random.randint(1,100)
if not(value in numbers):
numbers.append(value)
number = number + 1
# show unsorted list, sort the list, and show sorted list
print "Before:", numbers
sort(numbers)
print "After :", numbers
# File: 12-01.py
# Purpose: Example: a recursive function
# Programmer: Anne Dawson
# Course: CSCI120A, CSCI165
# Date: Thursday 11th November 2004, 14:25 PT
def factorial(n):
if n == 0:
return 1
else:
return n * factorial(n-1)
print " 5! has a value of: ",
result = factorial(5)
print result
print " 4! has a value of:",
result = factorial(4)
print result