Math 15Introduction to Scientific Data Analysis

Lecture 8Python Programming – Part 2

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Schedule

Final ExaminationDecember ?Final

Project #2Python Programming - #6December 515

Python Programming – #5November 2814

Quiz #6Python Programming – #4November 2113

No LectureNovember 1412

Quiz #5Python Programming – #2November 711

Python Programming – #1October 3110

Quiz #4Programming – Introduction to Python Part - IIOctober 249

Project #1Programming – Introduction to Python Part - IOctober 178

Quiz #3Excel #6 – Interactive ProgrammingOctober 107

Excel #5 – Data AnalysisOctober 36

Quiz #2Excel #4 – Regression AnalysisSeptember 265

Excel #3 – Statistical AnalysisSeptember 194

Quiz #1Excel #2 – Plotting Graphs/ChartsSeptember 123

Excel #1 – General TechniquesSeptember 52

Introduction to the data analysisAugust 291

Project DueConceptsDateWeek

Final ExaminationDecember ?Final

Project #2Python Programming - #6December 515

Python Programming – #5November 2814

Quiz #6Python Programming – #4November 2113

No LectureNovember 1412

Quiz #5Python Programming – #2November 711

Python Programming – #1October 3110

Quiz #4Programming – Introduction to Python Part - IIOctober 249

Project #1Programming – Introduction to Python Part - IOctober 178

Quiz #3Excel #6 – Interactive ProgrammingOctober 107

Excel #5 – Data AnalysisOctober 36

Quiz #2Excel #4 – Regression AnalysisSeptember 265

Excel #3 – Statistical AnalysisSeptember 194

Quiz #1Excel #2 – Plotting Graphs/ChartsSeptember 123

Excel #1 – General TechniquesSeptember 52

Introduction to the data analysisAugust 291

Project DueConceptsDateWeek

December 176-9pm

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Last Week!

First time of Python Programming

What did you think?

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October, 2007

Bis 180

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Any Questions?

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Assignment #5 due November 2nd, 2007!

Assignments & their materials!

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First, Retrieve this file.

For submission, first click this to attach your python codes.

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Click this to browse your file and attach your python file

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Then hit this to continue!

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To submit

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Any Questions?

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Reviews from 1st Programming Experience

Case sensitive Name1 = raw_input(“….. name1 = raw_input(“…..

If computer is asking questions, you need to respond!

name1 = raw_input("What is your name?")print "Hello, " + name1Python Program

IDLE 1.2.1 ==== No Subprocess ====>>> What is your name? MasaHello, Masa>>>

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What is a computer programming?

A computer programming is a sequence of instructions that specifies how to perform a computation.

Basically, all computers need someone to tell them what to do!

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Example – Conversion of US$ to Can$

$6.0$ CanUS 6.0$$ USCan

# # This program converts from US $ to Canadian $

us_money = input ("Money value in US $ ")

can_money = us_money /0.6

print "US$", us_money, " = Canadian $", can_money

IDLE 1.2>>> Money value in US $ 2.5US$ 2.5 = Canadian $ 4.16666666667>>>

Execute (F5 of Editing window)

us_money = 2.5

Variables

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Python 2.5.1Type "copyright", "credits" or "license()" for more information. >>> x = 2>>> x2>>> y = 1>>> y1>>> x + y3>>> y = x>>> x + y4>>>

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3 mistakes in this program.

# if statement

answer = raw_input("Do you like Mathematics? ")if answer == "yes":        print "That is great!"else:        print "That is disappointing!”

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Any Questions?

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Next Week

More Programming

while statement General loop

for loop statement A sequence iteration

List Mutable (changeable) arrays of object

reference: i.e. [0,1,2,3] [‘Lions’,”Tigers’,’Bears’,’Oh my’]

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Remember!

The process of learning to program is an excellent opportunity to practice problem-solving skills.

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Lists

A list is an ordered set of values, where each value is identified by an index. The values that make up a list are called its elements.

Examples:

var1 = [10, 20, 30, 40]

var2 = ["spam", "bungee", "swallow"]

var3 = ["hello", 2.0, 5, “UC Merced”]

a list of four integers. a list of three strings.

a list of mixing value types

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List operations

>>> a = [1, 2, 3] >>> b = [4, 5, 6] >>> c = a + b >>> print c [1, 2, 3, 4, 5, 6]

The + operator concatenates lists:

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List operations – cont.

>>> list = ['a', 'b', 'c', 'd', 'e', 'f']

>>> list[:4] [‘a’, 'b', 'c‘, ‘d’]

>>> list[3:]

['d', 'e', 'f']

>>> list[1:3]

['b', 'c']

The slice operations:

Up to 4th element

From 3rd element on

0th element 1st element

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List operations – cont.

>>> fruit = ["banana", "apple", "quince"] >>> fruit[0] = "pear"

>>> fruit[-1] = "orange"

>>> print fruit

['pear', 'apple', 'orange']

lists are mutable, which means we can change their elements.

0th Element

Last Element

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List operations – cont.

List deletion del removes an element from a list:

>>> a = ['one', 'two', 'three']

>>> del a[1]

>>> a

['one', 'three']

You can use a slice as an index for del: >>> list = ['a', 'b', 'c', 'd', 'e', 'f']

>>> del list[1:5]

>>> print list

['a', 'f']

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List operations – cont.

Append & Remove Syntax- list_name.append() & list_name.remove()

Example:ucm = [“shrimp", “hare", "eagle", “bobcat"]

print ucm

ucm.append("dog")

print "The zoo has the following animals:", ucm

ucm.remove("eagle")

print "The zoo has the following animals:", ucm

>>> [‘shrimp', ‘hare', 'eagle', ‘bobcat']The zoo has the following animals: [‘shrimp', ‘hare', 'eagle', ‘bobcat', 'dog']The zoo has the following animals: [‘shrimp', ‘hare', ‘bobcat', 'dog']

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Any Questions?

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while statement

Computers are often used to automate repetitive tasks. Repeating identical or similar tasks without making errors is something that computers do well and people do poorly.

The first feature we are going to look at is the while statement. The while statement continuously performs an

action while a condition is true.

while <condition>:<commands>

Syntax

The while command first checks if the condition is true or false and then execute the command(s) if true.

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while statement – cont.

Example

N = 10 # Set the initial# value of N

while N > 0: print N N = N-1print "Blastoff!"

>>> 10987654321Blastoff!This program reads:

"While N is greater than 0, continue displaying the value of N and then reducing the value of N by 1. When you get to 0, display the word Blastoff!"

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while statement – cont.

Here is the flow of execution for a while statement: 1. Evaluate the condition, yielding false or true.2. If the condition is true, execute each of the

commands in the body and then go back to 1.

3. If the condition is false, exit the while statement and continue execution at the next statement.

while <condition>:<commands>

<next statements>

Syntax

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Any Questions?

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for loop statement

Another operation for repetitive tasks is for loop statement.

Each time through the loop, the next character in the string or next value in the value list is assigned to the variable, jj. The loop continues until no characters or values are left.

for jj in (list):<commands>

Syntax

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for loop statement – cont.

fruit = ["banana","apple","orange"]for masa in fruit: print masa

Examples>>> bananaappleorange

N = 10for var0 in range(N): print var0

>>>0123456789

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for loop statement – cont.

N = 10for var in range(1,N,2): print var

Examples>>> 13579

N = 15icount = 0 # Intializing a variablefor var in range(1,N,2): icount = icount + 1 print var, icount

>>> 1 13 25 37 49 511 613 7

Starting Value

End Value

Increment

Counter

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Any Questions?

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Homework #5 due November 2nd

Already available in UCMCROP

Here comes Quiz #4!