CMSC $135$ Introduction to Scripting

Lab $-$ Hacker Speak and Credit Card Hide

Scope:

In this lab, students will :

$$ Write and run Python Script.

$$ Learn how to work with strings.

$$ Learn how to find and replace parts of a string.

$$ Learn how recursion works in Python.

Equipment$/$ Tool Needed:

This lab requires the use of the following:

$$ Laptop $/$ Desktop

$$ Any version of Windows

$$ Any Web$-$Browser

$$ IDLE IDE

Lab Outcomes:

Upon completion of this lab, students will be able to:

$$ Understand basic structures and algorithms.

$$ Properly apply basic programming constructs and concepts including:

$$ Variables and types$($int$,$ float, char, etc.$)$

$$ Strings, arrays, structures

$$ Sequential execution

$$ Assignments $(=,+,-,*,/,\%,$ etc.$)$

$$ Decisions and branching$($if$,$ if$...$else, elseif, etc.$)$

$$ Functions, procedures, and calls

$$ Loops$($for$,$ while, repeat, etc.$)$

$$ Debugging techniques

$$ Write simple linear scripts.

$$ Implement basic security concepts.

$$ Permissions, bounds checking, input validation, type checking and parameter validation.

$$ Write simple and compound conditions within a programming language.

$$ Basic Boolean logic$/$operations$.$

$$ AND$/$OR$/$NOT

$$ Run Python Scripts.

Steps:

$$ The following steps will be completed and submitted via a Microsoft word file along with Python source code file. Any other format will not be accepted and will result in a zero grade. Programming Labs are considered incomplete, if they do not compile and will result in a zero grade.

$$ Check System Requirements

$$ Check the system requirement to know whether your computer supports IDLE.

$$ Download and Install IDLE $($Refer to Python Installation Lab$)$

$$ H$4$ch$3$r Sp$34$k

Create a function that takes a string as an argument and returns a coded $($h$4$ck$3$r $5$p$34$k$)$ version of the string.

Your code must accept user input and produce a printed output statement.

Examples:

hacker$\_$speak$("$javascript is cool"$)"$j$4$v$45$cr$1$pt $15$ c$00$l$"$

hacker$\_$speak$("$programming is fun"$)"$pr$0$gr$4$mm$1$ng $15$ fun"

hacker$\_$speak$("$become a coder"$)"$b$3$c$0$m$34$ c$0$d$3$r$"$

Notes:

In order to work properly, the function should replace all $"$a$"$s with $4,"$e$"$s with $3,"$i$"$s with $1,"$o$"$s with $0,$ and $"$s$"$s with $5.$

Hint:

Python string method replace$()$ returns a copy of the string in which the occurrences of old have been replaced with new, optionally restricting the number of replacements to max.

Syntax:

Following is the syntax for replace$()$ method $$

str$.$replace$($old$,$ new$[,$ max$])$

Parameters:

old $$ This is old substring to be replaced.

new $$ This is new substring, which would replace old substring.

max $$ If this optional argument max is given, only the first count occurrences are replaced.

$$ Hiding the Card Number

Write a function that takes a credit card number and only displays the last four characters. The rest of the card number must be replaced by $************.$

Your code must accept user input and produce a printed output statement.

Be sure to include input validation condition into your program.

Examples:

card$\_$hide$("1234123456785678")"************5678"$

card$\_$hide$("8754456321113213")"************3213"$

card$\_$hide$("35123413355523")"**********5523"$

Notes:

$$ Ensure you return a string.

$$ The length of the string must remain the same as the input.