MEMORANDUM
TO: Dr.
Roberta Albi
FROM: Erika Siebring
CC:
ENG 131 Class
DATE: July 14, 2018
RE: How
to Code a Mad Lib in Python Programming
_____________________________________________________________________________
Problem Statement
Problem
Computer programming and
creating a sample of computer code are not considered common knowledge. Thus it
is unlikely the majority of the ENG 131 class has knowledge of the Python
programming software, how to use it or how to create computer code in general.
Purpose and Findings
Purpose
This report will detail
how to download the Python computer software and write code that creates a
single Mad Lib. A Mad Lib is a word game in which an individual produces
various words (i.e. noun, adjective, verb) that are
substituted for blanks in a narrative template.
Findings
The Python software is a
user-friendly introduction to computer programming. A Mad Lib is a simple
template to explain how the software functions.
Recommendation
Individuals in the ENG
131 class should continue to explore the uses of Python as knowledge of it can
be applicable to different areas in an individual’s life.
Table of Contents
Executive Summary
Introduction
Purpose
Problem
Audience
Background
Scope
Installation
of the Python Software
Python
Dashboard
Python Shell
Creating a New File
Important
Terms & Symbols
Addition Sign
Comment Sign
Expression
Input
Output
Print Statement
Program
Quotation
Marks
String
Variables
Coding
a Mad Lib
“Hello World” Example
Introduction to Mad Libs
Initiating a Mad Lib Program
Creating Mad Lib Variables
Implementing Groups of Mad Lib
Variables
Creating a Story with the Mad Lib
Variables
Executing a Mad Lib Program
Common
Errors
General Error Messages
Syntax Errors
Runtime Errors
Semantic Errors
Conclusion
Works
Cited
Introduction
Purpose
Problem
Not every individual
knows how to create computer code or understands the first steps of computer
programming. The ENG 131 class most likely falls into this category and does
not have knowledge of Python programming.
Audience
The ENG 131 class is the
primary audience and main stakeholder. This document is designed to introduce
the class to the Python software and how to create computer code. The secondary
audience is Dr. Roberta Albi.
Background
Started in 1991, Python
programming is an object-oriented computer coding language and its software can
be downloaded on several different computers. Its simple syntax is widely considered
to be one of the easiest platforms to introduce individuals to computer coding.
This software is used for general purposes. The official Python website
provides various beginner tutorials and its companion website, learnpython.org,
is dedicated to helping viewers understand terms and functions within Python.
Numerous instructional textbooks have been written about Python as well.
Scope
The scope of this
project is to explain how to download the Python software and manually code and
print one Mad Lib. This includes descriptions of Python’s features and
instructions on how to manipulate and print different variables within computer
code.
Installation of the
Python Software
Free Python downloads
are on python.org. SCROLL down the homepage to the ‘Download’ section and click
on the latest Python edition (Downloads). A webpage entitled ‘Python 3.7.0’
will appear. The webpage’s name may change as new editions are released. SCROLL
down to ‘Files’ where there are versions of Python available for Windows and
Mac OS X operating systems (Downloads).
Click on the ‘executable
installer’ or ‘installer’ file that corresponds to the computer’s operating
system (Downloads). Both the 32-bit and 64-bit systems are available and functional
for the Mac OS X system. Click ‘Install Now’ in the pop-up window. The online
Python tutorial will be available once the software is installed. Search the
computer for ‘Python’ or ‘IDLE’ to access the software. The Python Shell window will
open.
Python Dashboard
Python Shell
The Python Shell window is
also called the interpreter (Downey 2).
This is where computer code is read and executed. At the top of the Shell
window there are various tabs, including ‘File,’ ‘Edit’ and ‘Shell.’ Each of
these tabs have various functions listed within them.
The >>> line is the prompt (Downey 2). All code in the Shell is written
after the prompt.
Creating a New File
Computer code can be
stored and tested in a file separate from the Shell. Go to the ‘File’ tab in
the Shell window and select ‘New File.’ A new file labeled ‘Untitled’ will pop
up. Code can be stored in this document, either on a computer or on a flash
drive. When saved, the file label will end with ‘.py.’
Go to the ‘Run’ tab in the new file and select ‘Run Module’ to execute any code
stored in it. The file will require you to save before closing it. When executed,
the code’s result will appear in the Shell window.
Important Terms & Symbols
Addition Sign (+)
The + sign works in two ways.
It can add two or more whole or decimal numbers (Downey
2). It can also conjoin several pieces of text (Downey 12), or conjoin a
punctuation mark with a variable or set of text (See also ‘Variables’
on pg. 7).
Typing an addition
problem after the >>> prompt will result in the sum being printed on
a new line. Typing a word followed by + and a comma will result in the word being
printed on a new line with a comma next to it (See also ‘Print
Statements’ on pg. 6).
Figure 1: Symbol
Functionality in Python Programming
The symbols in Figure 1
are typically found in mathematics and are used to evaluate numbers in Python. Source: Ekmekci, Berk,
et al. "An Introduction to Programming for Bioscientists:
A Python-Based Primer." Plos
Computational Biology, vol. 12, no. 6, 2016, pp. 1-43. EBSCOhost,
doi:10.1371/journal.pcbi.1004867.
Comment Sign (#)
The # sign differentiates the functional code from programming
information. Any text after this sign is a comment and will be red. Comments in a file often include a file’s name,
date, author and description of the code’s functionality. Comments also tell a
programmer what each section of code does. Comments can be written after the >>> prompt or in a file.
Expression
An expression is a
single line of code (Downey 10). An expression can print text, evaluate numbers
or assign a value to a variable.
Input
An input is any data (i.e.
numbers, equations) the programmer types within the Shell or a file (Downey 1).
Anything following the >>> prompt is an input. Input statements are purple and are written as input(). They can be used to prompt a response from the programmer.
For this project, this response will be typing in a word needed for the Mad
Lib.
Output
An output is the result
of executing an expression (See also ‘Expression’ on pg. 6).
Outputs are blue on a new line in the Shell (Downey 1), below the
>>> prompt. If an addition problem is typed after
the prompt, the sum is the output. To produce an output, enter an input into
the Shell and hit ENTER.
Print Statement
A print statement is purple and tells the computer to print an expression (Downey
7). Beginning with print(), anything the
programmer wants printed goes in the parentheses. Once executed, the output will
appear in the Shell on a new line. Print statements with text require either
single or double quotation marks within the parentheses (See also ‘Quotation
Marks’ on pg. 6). Print statements with integers don’t require quotation
marks. To execute printing in the Shell, hit ENTER.
To print a number, type
out the print statement after the >>> prompt and put the number inside the
parentheses. The number will be printed on a new line. Follow this same process
when printing a variable (See also ‘Variables’ on pg. 7). To
print text, type out the print statement and put the text, in quotation marks,
inside the parentheses. The text will be printed on a new line.
Program
A program is a sequence
of code performing one or more tasks (Downey 6). A program is stored in a
Python file on either a computer or flash drive. For this project, the entire
Mad Lib will be considered one Python program.
Quotation Marks
Quotation marks, single
or double, indicate words or sentences. Any text inside quotation marks will be
green and will be printed (See
also ‘Strings’ on pg. 7). Quotation marks are not needed for
numbers or variables (See also ‘Variables’ on pg. 7). Not
including quotation marks when printing text will result in an error.
Putting double or single
quotation marks around the text in a print statement will result in the same
output. Typing text with quotation marks immediately after the >>> prompt will produce the same output. Typing text
without both the beginning and end quotation marks will result in an error.
String
A string is an
expression with text. It is called this because all the letters or characters
are “strung together” (Downey 4). A string must be in quotation marks in order
to be printed.
Figure 2: Strings in
Python Programming
The variable in Figure 2
is named ‘mystring,’ which has the assigned value of
‘hello.’ When the variable is printed, the result will be ‘hello.’ Source: "Variables and Types." Learn Python, n.d., www.learnpython.org. Accessed 16
June 2018.
Variables
A variable is a name
that refers to a value (Downey 9). This value can be a number or string.
Variables cannot start with a number or be a Python keyword (Downey 10). Keywords
are orange and perform functions not described in this document. Attempting
to use a keyword as a variable will result in an error. A variable does not
need quotation marks.
A variable can be given
a number value by typing the name of the variable, an equal sign, and a number.
A print statement with the variable name in the parentheses will produce the
number as an output. A variable can have a string value by following the same
process and putting the string in quotation marks. The print statement will
return the string as an output.
Python’s keywords
include: False, None, True, and, as, assert, break, class, continue, def, del, elif, else, except, finally, for, from, global, if, import, in, is, lambda, nonlocal, not, or, pass, raise, return, try, while, with, yield (Downey 10).
Coding a Mad Lib
“Hello, World!” Example
The most basic computer
exercise is the “Hello, World!” program (Perkel 125).
It’s the first expression typed when working with a new coding language. Programming
a Mad Lib is similar to the “Hello, World!” print statement.
A print statement with
the text “Hello,
World!” in the parentheses can either use single or double quotation marks.
Both result in the Hello, World! output.
Introduction to Mad Libs
A Mad Lib is a word game
where an individual produces various words (i.e. noun, adjective, verb) that are substituted for blanks in a narrative
template. This project will create an introductory message explaining the
directions and several expressions asking for user input. The result is an
entire printed Mad Lib.
Initiating a Mad Lib
Program
Open the Python
software. Go to the ‘File’ tab and select ‘New File.’ A new, untitled file will
appear. Title this file ‘Movies Should Be Fun Mad Lib.’
In the ‘Movies Should Be
Fun’ file, create a large rectangle using the # symbol. Everything typed
inside the box will now be a comment. Put the title of the file inside the box at
the center top. Move the cursor down a few lines. Type Programmed by followed by your name and the date and align it
to the left. Move the cursor down two lines. Type Description: followed by a few sentences
explaining how this project will create one Mad Lib. For easy reading,
begin typing the description and stop when the words stop fitting inside the box.
Move the cursor underneath the first line and type the remainder of the description.
Delete any unnecessary spaces until the # symbols form straight
horizontal and vertical lines.
Move the cursor outside
the bottom right corner of the box. Hit ENTER and create a #Intro comment.
Hit ENTER again and create an input statement. In the parentheses, create a
string that welcomes the user to the Mad Lib. When the program is executed,
this expression will greet the user.
Creating Mad Lib
Variables
Hit ENTER twice and
create a #User Input comment.
This indicates the start of the Mad Lib. Hit ENTER and type nounBuildings to create the first variable. Type an equal
sign and an input statement. In the parentheses, create a string that asks the
user to enter a plural noun. Finish the string with a space, and an arrow made
of an equal sign and a greater-than sign. When the program is executed, this expression
will ask the user to type in a plural noun for the Mad Lib. That plural noun
will be the variable nounBuildings’s value.
Implementing Groups of
Mad Lib Variables
Now one variable with one
Mad Lib component has been created. More variables will be created and assigned
values using the above structure. Hit ENTER and type adjectiveExtinct to create the second variable. Type an equal
sign and an input statement. In the parentheses, create a string asking the
user to input an adjective. Finish the string with a space, and an arrow made
of an equal sign and a greater-than sign. When the program is executed, this
expression will ask the user to type in an adjective for the Mad Lib. That
adjective will be the variable adjectiveExtinct’s value.
Hit ENTER and create the
variable nounMonsters followed by an equal sign and an input statement. In the parentheses,
create a string asking the user to input a plural noun and finish it with a
space and an arrow. Like the other expressions, this will ask the reader for a
different part of the Mad Lib. This pattern will continue through all the
following expressions.
Hit ENTER and create the
variable nounBed
followed by an equal sign and an input statement. In the parentheses, create a
string asking the user to input a noun. Finish the string with a space and an
arrow.
Hit ENTER and create the
variable adjectiveWholesome followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input an adjective. Finish the
string with a space and an arrow.
Hit ENTER and create the
variable nounLife followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input a noun. Finish the string
with a space and an arrow.
Hit ENTER and create the
variable nounWind followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input a noun. Finish the string
with a space and an arrow.
Hit ENTER and create the
variable personintheroomSmith followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input the name of a person.
Finish the string with a space and an arrow.
Hit ENTER and create the
variable placeWashington followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input the name of a place.
Finish the string with a space and an arrow.
Hit ENTER and create the
variable adjectiveWarm followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input an adjective. Finish the
string with a space and an arrow.
Hit ENTER and create the
variable personintheroomHardy followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input the name of a person.
Finish the string with a space and an arrow.
Hit ENTER and create the
variable personintheroomCostello followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input the name of a person.
Finish the string with a space and an arrow.
Hit ENTER and create the
variable adjectiveFunny followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input an adjective. Finish the
string with a space and an arrow.
Hit ENTER and create the
variable nounComedyRoutines followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input a plural noun. Finish the
string with a space and an arrow.
Hit ENTER and create the
variable partofthebodySides followed by an equal sign and an input statement. In the
parentheses, create a string asking the user to input a plural part of the
body. Finish the string with a space and an arrow.
Creating a Story with
the Mad Lib Variables
Each variable will be incorporated
into a narrative. Hit ENTER and create a #Print Story
comment. Hit
ENTER again and create a print statement under the comment. In the parentheses,
type the string: "In recent years, there have been too many disaster movies
in which tall". This will be printed when
the code is executed. After the end of the string, type a comma, nounBuildings and another comma. When the program is executed,
the variable nounBuildings will be printed immediately after the end of the string.
Hit ENTER and create a
new print statement. In the parentheses, type the string "catch on
fire," followed by a comma, adjectiveExtinct, and a comma. Type the string "dinosaurs come to life, and
huge", then a comma, nounMonsters, a comma, and the string "attack people in
the". When executed, this
will print the variables and strings as part of the narrative.
Hit ENTER and create a
new print statement. In the parentheses, type the string "ocean, making
you afraid to get out of your”, then a comma, nounBed, a comma and the string "in the morning.".
Hit ENTER and create a
new print statement. In the parentheses, type the string "Movie fans ask
why we can't have more”, then a
comma, adjectiveWholesome, a comma, the string "pictures like It's a Wonderful” another comma, and then nounLife with a + and the string “,”.
Hit ENTER and create a
new print statement. In the parentheses, type the string "Gone with the”, then a comma, nounWind, a +, and the string ", or Mr.". Type a comma, personintheroomSmith, a comma, the string "Goes to", a comma and placeWashington with a + and the string “.”.
Hit ENTER and create a
new print statement. In the parentheses, type the string "These films made
you feel", then a comma, adjectiveWarm, a comma and the string "all over. These
same fans also ask why we can't".
Hit ENTER and create a
new print statement. In the parentheses, type the string "have more funny
films with comedians such as Laurel and" and then a comma. Type personintheroomHardy, a +, the string ", and Abbott and", a comma, personintheroomCostello, a + and the string “.”.
Hit ENTER and create a
new print statement. In the parentheses, type the string "These" and a comma, adjectiveFunny, a comma and the string "performers gave
us great slapstick".
Type a comma, nounComedyRoutines,
a comma, the string "that still makes our", a comma, partofthebodySides and a comma.
Hit ENTER and create a
new print statement. In the parentheses, type the string "ache from
laughing.".
Hit ENTER and create the
nounTheEnd variable with an equal sign and an input statement. In the parentheses,
type the string “The End”.
When the program is executed,
each print statement will print a portion of the Mad Lib. When variable names
are followed by + and a comma, the + adds a comma into the printed text.
Executing a Mad Lib
Program
To execute the program, go
to the ‘Run’ tab at the top of the file and select ‘Run Module.’ Hitting F5
will also execute the program. The file will automatically save before
executing. The Python Shell window will open and print the welcome message in
blue.
Hit ENTER to continue. The
next line will ask you to input a plural noun. Type in a
plural noun of your choice. Hit ENTER. The next line will ask you to
input an adjective. Type in an adjective of your choice. Hit ENTER. Continue this process until the Mad Lib program
prints the full narrative. The full output will look like this:
In recent years, there
have been too many disaster movies in which tall Input catch
on fire, Input dinosaurs
come to life, and huge Input attack people in the
ocean, making you afraid to get out of your Input in the
morning.
Movie fans ask why we
can't have more Input pictures
like It's a Wonderful Input, Gone with the Input, or Mr. Input Goes to Input.
These films made you
feel Input all
over. These same fans also ask why we can't have more funny films with
comedians such as Laurel and Input, and
Abbott and Input.
These Input performers gave us great
slapstick Input that still makes our Input ache from laughing.
The End.
In this output, ‘Input’
replaces the user-inputted values. Hit ENTER to end the program. The >>> prompt to appear. Hit F5 or select ‘Run Module’ in
the file window to execute the program again. The narrative will change
slightly if the user inputs different values.
Common Errors
General Error Messages
A programmer can make
mistakes when creating code. A mistake in the ‘Movies Should Be Fun’ file will
cause the code to stop executing. If so, a separate window will open indicating
the error type and the affected line of code.
If a mistake occurs in
the Python Shell, a red error message will print.
Syntax Errors
Syntax errors are the
most common type of error. These occur when the code structure is incorrect or
incomplete (Downey 13). Common syntax errors are:
I.
Forgetting the Quotation
Marks
There are two ways an error like this can look.
If after the >>> prompt a string is typed without an ending
quotation mark, the error SyntaxError will appear.
If a print statement includes text without
quotation marks, the error Traceback: NameError will appear.
To fix the first error, complete the string with
an end quotation mark. To fix the second error, include quotation marks around
the text inside the print statement’s parentheses. Review ‘Quotation Marks’
in the Important Terms section for more information.
- Forgetting a Parenthesis
This error occurs when including only one
parenthesis in a print statement.
In the Shell, the cursor will stay under the
incomplete print statement until it’s completed with another parenthesis. In a
program file, the same error will read:
Unexpected EOF while
parsing. Add another parenthesis.
- Forgetting a Comma
This error occurs when forgetting a comma when
combining a string and a variable in a print statement. This will result in a SyntaxError.
To fix this error, add a comma in between the
end of the string and the variable.
- Typing an Invalid Variable Name
This error occurs when attempting to create a
variable with a Python keyword. This will result in a SyntaxError error. This error also occurs when a previously-used
variable name is misspelled.
To fix the first error, pick a new variable. Review
‘Variables’ in the Important Terms section for more information. To fix the
second error, review the program to make sure all variables are spelled
correctly.
Runtime Errors
Runtime errors occur
while the program executes (Downey 14). If an error is found, the program will
stop and return an error message. A red bar will appear where the mistake is.
Review the program carefully to fix the error.
Semantic Errors
Semantic errors occur
when a program’s result does not say what the programmer wants (Downey 14). Semantic
errors include misspelling a string or forgetting punctuation in a string.
Closer evaluation is needed.
Conclusion
This report explored the
functionality of Python programming and the common errors that prevent the
functionality of a program. Educating the 131 class about Python will result in
the spreading of computer programming knowledge and knowledge of how computers
work. This could in turn be useful for personal fulfillment or professional
work. It is recommended that those whom are interested in computer programming
continue to expand their knowledge on the subject.
Works Cited
Downey, Allen B. Think
Python: How to Think like a Computer Scientist, ed. 2, no. 2.2.23, 2015,
pp. 1-244. O’Reilly Media, Inc., greenteapress.com/thinkpython2/thinkpython2.pdf. Accessed 16 June 2018.
“Downloads.” Python,
2001, www.python.org. Accessed 16 June 2018.
Perkel, Jeffrey M.
"Programming: Pick up Python." Nature, vol. 518, no. 7537,
2015, pp. 125-126. EBSCOhost, doi:10.1038/518125a.