As usual, create a directory to hold today's files. All programs that you write today should be stored in this directory.
$ cd ~/cs120/labs
$ mkdir lab19
$ cd lab19
Write a function
called append_exclamation(a_phrase), which
takes a string as a parameter. This function should return a
string, which
is simply a_phrase with an exclamation point appended
to the end.
Write a function called get_extents(a_phrase), which
takes a string as a parameter. This function should return a
string, which contains only the first and last characters
from a_phrase.
Passwords are possibly the most important way that individuals can ensure their own safety on the Internet. However, it is also typically the easiest thing for a hacker to figure out, or to get their hands on. This is simply because most Internet users choose incredibly weak passwords. The easiest way to get around this issue to to use a randomly generated password.
Write a function called generate_password(size), which
takes a positive integers as a parameter. Your program should
return a string of lower case letters of the specified size. This
function should randomly choose the lower case letters in the
returned string.
Your program should ask the user for a password length, and print to the terminal the password you generate.
Make sure you test your program well. How many test cases do you need? Make sure you follow all of the course's coding conventions.
$ python3 password_generation.py How long do you want your password? 5 neolp $ python3 password_generation.py How long do you want your password? 10 wigmnhgqwn
Since you only need to generate lower case passwords, you
can use the string.ascii_lowercase constant to
access letters from that range.
You can use the random module to generate
random numbers. Since we know we are generating lower-case
characters, you need to generate a random number to use as
an index in the
string.ascii_lowercase string.
Since you know how many characters you want, you should use a for loop for this activity. You are also using the accumulator pattern again, but with strings this time.
Even random strings of lowercase characters are pretty easy to break. A better program would randomly decide to include some uppercase letters as well. Alter your function so that it will sometimes include uppercase letters in the generated passwords. Make sure the parameter used to determine how often an uppercase character is used is well documented and easily altered.
Some states require that legal documents not be written above a certain grade level. The Flesch-Kincaid grade level is a numeric score that indicates the minimum grade level in which an average student would be able to understand a text. Writing a function that computes the grade level of text requires being able to count the number of occurrences of certain characters.
In a file called reading_level.py write the
function compute_reading_level(text). The function
should return the Flesch-Kincaid grade level of the input text. The
Flesch-Kincaid grade level equation requires determining the number
of syllables in a sentence, which is very difficult for a program to
compute without a dictionary. The following equation is an
approximation to the Flesch-Kincaid grade level that does not use
syllables:
$$0.39\cdot(W/S)+11.8\cdot((L/3)/W)-15.59$$
Where \(W\) is the total number of words, \(S\) is the total number of sentences, and \(L\) is the total number of letters. Assume that all sentences end in a period, that all words are separated by a single space, and that all characters that are not a space or period are letters.
| Function Parameters | Expected Output |
|---|---|
| 'I do not like them Sam I am. I do not like green eggs and ham.' | -1.4075 |
| 'To be or not to be that is the question. Whether tis nobler in the mind to suffer the slings and arrows of outrageous fortune or to take arms against a sea of troubles and by opposing end them.' | 7.445769230769233 |
Determining the number of words requires counting the number
of space characters and determining the number of sentences
requires counting the period characters. Instead of writing
code to count each of these characters separately, write a
function count_character(character, text) that
counts the number of times character occurs
in text. The function should use an
accumulator variable to count and a for loop to traverse the
text one character at a time. For each character in the text
that is equal to input character, increment the counter.
Use the above function to determine the number of words and sentences. Determine the number of letters by using the length of the input text and the number of non-alphabetic characters. Before computing the reading level, test your code by printing the number of words, sentences, and letters on short examples.
The character count function was easy to write because it assumes that the input text only has alphabetic characters, single space characters, and period characters. This isn't very useful because most text does not conform to these restrictions. Modify the function so that it can work for any text. It should: