For lab 5, please do the following exercise
Word & character counter
Download the text file from hereLinks to an external site.. You'll write a program called
word_count.py that prompts the user for a file name, then prints out counts of words, non-whitespace characters (including punctuation), and alphanumeric characters (letters and numbers, excluding punctuation), like this:
$ python word_count.py Enter the file name: corpse_bride.txt Words: 480 Characters: 2465 Letters & numbers: 2379
If the user enters an invalid file name the program should exit gracefully with the message
Can't open <file_name>, like this:
$ python word_count.py Enter the file name: copse_brode.txt Can't open copse_brode.txt
If you've looked at homework 5, you'll recognize a lot of what you have to do here.
Opening a file and reading it line by line is easy in Python. Read the docs about
open() here: https://docs.python.org/3/library/functions.html#openLinks to an external site.
The name of the file will be passed in by the user after a prompt. The
open() function takes a string argument representing the name of the file, and returns a file object. The file object will behave as a generator for lines of the file. This means that you can use a plain
for loop to loop through the lines of the file.
A user inputting an invalid file name is a good example of what's called an exception in programming. An exception is a possible state of the system that is not a part of the designed behavior of the system. Exception handling requires anticipating possible things that could go wrong and making sure that they are dealt with by the program in a useful and clear way.
Python's exception handling is done using
except: blocks. Python tries to execute the code in the
try: block. If it executes successfully, then the code proceeds to execute as expected. If the code in the
try: block raises an exception, then the code in the
except: block will be executed instead. Read the documentation for exception handling here: https://docs.python.org/3/tutorial/errors.html#handling-exceptionsLinks to an external site.
except: blocks to give the the user receives a user-friendly message if they enter an invalid file name. After printing the message to the screen, you can call
return which will end the execution of the function (this assumes that your code is in a
main function, as it should be!)
Pattern matching with regular expressions
For getting the word count and the character count, string methods such as
.split()Links to an external site. and
.replace()Links to an external site. and the
len() function should give you all you need.
For more sophisticated pattern matching, such as matching all alphanumeric characters, you'll probably want to use regular expressions (regexes). This requires importing the
re library. Specifically,
.findall()Links to an external site. will return a list of all matches of whatever regular expression pattern you pass it. Check out the Regex How-ToLinks to an external site. for an introduction. If you're feeling pressed for time, search that document for
alphanumeric to see how to represent alphanumeric (letter or number) characters as a regex pattern.
word_count.py to Canvas.
It's a Dead Scene, but That's a Good Thing By MANOHLA DARGIS (New York Times) A necro- philiac entertainment for the whole family to enjoy, "Tim Burton's Corpse Bride" marks the director's latest venture into the world of stop-motion animation, following "Tim Burton's The Nightmare Before Christmas" and "James and the Giant Peach." As in "Nightmare," kooky and spooky things go bump in the night, this time in the service of a lightly kinked romance about a melancholic boy, the girl he hopes to marry and the bodacious cadaver that accidentally comes between them. Directed by Mr. Burton and Mike Johnson, and written by John August, Caroline Thompson and Pamela Pettler, the story hangs on a timid bachelor with matchstick legs and a pallid complexion, Victor (voiced by Johnny Depp), whose upwardly mobile parents arrange his marriage to Victoria (Emily Watson), the retiring daughter of impoverished gentry. When the wedding rehearsal goes kablooey, Victor retreats into the woods, whereupon he becomes the reluctant object of desire of the Corpse Bride, a blue-tinted beauty with gnawed-through limbs and a miraculously preserved bosom (Helena Bonham Carter, the director's very alive partner). Together, the eerie couple descends into the land of shades, inducing Victor to trade the world of the barely living for the land of the exuberantly dead. For Victor and for his two directors, the underworld soon proves a more hospitable place than the world above, and far more entertaining. Above, the living shuffle about as somnolently as zombies amid a rainbow of gray, while down below, the walls are splashed with absinthe green, and the skeletons shake, rattle and roll. Bursting with mischief and life of a sort (think the grinning skulls of the Mexican artist JoseGuadalupe Posada), these skeletons dance themselves to pieces for a bravura musical number marred only by the composer Danny Elfman's insistence on recycling the same string of notes again and again. The notes reverberate more pleasantly when a gathering of spiders mend Victor's suit, notably because they trill a Gilbert and Sullivan pastiche as they stitch. It all ends happily ever after, of course, though not before Mr. Burton and company have gathered the dead with the undead, and given a kick in the pants to a pinched-faced pastor even more shriveled than the bride herself. The anticlerical bit gives the story a piquant touch, while the reunion between the corpses and the ostensibly living further swells the numbers of zombies that have lately run amok in the movies. Cinema's reinvigorated fixation with the living dead suggests that we are in the grip of an impossible longing, or perhaps it's just another movie cycle running its course. Whatever the case, there is something heartening about Mr. Burton's love for bones and rot here, if only because it suggests, despite some recent evidence, that he is not yet ready to abandon his own dark kingdom.
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