Assignment 2 String Processing

CS1026A, Computer Organization
Assignment 2
General Instructions: This assignment consists of 3 pages, 1 exercise, and is marked out
of 100. Assignments are the independent work of each student. Software may be used to
detect cheating.
Non-Functional Code Instructions:
1. Include brief comments in your code. Identifying yourself (the code’s author) by name
and user ID in the initial comment header. Comment also on key instructions and
calculations in your code.
e.g. ##
# A program for computing areas with inscribed circles.
# Student Name: Alex Brandt
# Student ID: abrandt5
2. Follow good coding style and normal Python conventions. This includes, but is not
limited to:
(i) Meaningful variable names.
(ii) Conventions for naming variables and constants.
(iii) Use of constants over “magic numbers”.
(iv) Readability: indentation, appropriate white space (blank spaces) within instructions, consistency in the use of all of the above.
Evaluation:
1. Functional Requirements:
(i) Does your module correctly implement the four validation functions?
(ii) Does your main program behave according to the specifications?
(iii) Does your main program handle invalid input?
(iv) Does your main program output values according to the specifications?
2. Non-Functional Requirements (above).
3. Ability to follow directions precisely.
Submission Instructions: Your submission should include exactly two files (zipped into
a zip file, if you’d like). These two files are: stringvalidation.py and userid_main.py
where userid is replaced by your UWO User ID (everything preceding “@” in your UWO
email; e.g. abrandt5). The contents of these two files are described below.
Learning Outcomes: In this assignment we will look at using loops, functions, and userdefined modules to facilitate some basic string processing.
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Exercise 1. This problem deals with form validation. Anyone who has created accounts
online or made purchases online should be aware of form validation. This process is all about
checking if the data the user has entered matches some pre-defined pattern. For example, a
credit card number should be 16 digits long, possibly with a hyphen (-) between each group
of 4 digits. In this exercise we look to define several different functions for validating several
different kinds of input. The guidelines for accomplishing this task are broken into two parts.
Part 1. In this section we will define the contents of the stringvalidation.py file. In
this file we look to implement four functions: checkName, checkEmail, checkPassword, and
checkAddress. Each function follows a common scheme:
1. Each function takes one string parameter as input.
2. Each function returns a Boolean value to indicate if the input string is “valid”. The
functions returns True if the input is valid and False otherwise.
3. If an input string is invalid, the function prints a message to indicate why the string is
invalid.
For each function, what determines if a string is “valid” depends on the particular function.
The following criteria certainly do not define all possible valid, for example, emails, but you
should limit your validation to only the following criteria.
1. The function checkName determines if the input string holds a valid first name and last
name based on the following criteria:
(a) The string must be at least 1 alpha character (i.e. a-z or A-Z) followed by a blank
space character ( ) followed by at least 1 alpha character,
(b) The first character of the string must be upper case,
(c) The first character after the blank space must be upper case,
(d) Hyphens (-) are valid as long as there are alpha characters to both the left and
right of each hyphen.
2. The function checkEmail determines if the input string is a valid email address based
on the following criteria:
(a) The string begins with some positive number of alpha characters or numeric characters (0-9), followed by
(b) The @ character, followed by
(c) Some number of alpha characters, followed by
(d) A period (.), followed by
(e) One of: “com”, “net”, “org”, “ca”.
3. The function checkPassword determines if the input string is a valid password based
on the following criteria:
(a) There is at least one lower-case letter,
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(b) There is at least one upper-case letter,
(c) There is at least one number,
(d) There are no spaces,
(e) The password is at least 8 characters long.
4. The function checkAddress determines if the input string is a valid address based on
the following criteria:
(a) The string begins with one or more numeric characters (0-9), followed by
(b) A black space character ( ), followed by
(c) One or more words containing only alpha characters (i.e. a-z or A-Z, there are no
numbers or special characters).
Part 2. In this section we define the contents of the userid_main.py file. In this file
you shall import your other file (e.g. by the command from stringvalidation import
checkName, checkEmail, checkPassword, checkAddress) and then use those imported
functions within your main function to prompt the user for inputs continuously until all
inputs are validated. In particular, your main function should:
1. Prompt the user for their first and last name and store this value in a variable. Using
the checkName function, determine if the input name is valid. If not, prompt the user
again to enter their name again. Continue this process until a valid name is obtained.
2. Prompt the user to input a valid email address and store this value in a variable. Using
the checkEmail function, determine if the input email is valid. If not, prompt the user
again to enter another valid email address. Continue this process until a valid email
address is obtained.
3. Prompt the user to input a valid password and store this value in a variable. Using the
checkPassword function, determine if the input password is valid. If not, prompt the
user again to enter another password. Continue this process until a valid password is
obtained.
4. Prompt the user to input a valid street address and store this value in a variable. Using
the checkAddress function, determine if the input address is valid. If not, prompt the
user again to enter another street address. Continue this process until a valid street
address is obtained.
5. Once all four inputs are validated, print the following message to the user:
Thank you, <name.
Your email is: <email
Your password is: <password
Your address is: <address
Where each of <name, <email, <password, and <address are replaced by the
validated strings which the user has input.
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