Pollyanna posted:

So how do I handle when the page is first loaded? I'm expecting the user to load the page, attempt to search from the searchbar, and if the input is blank or none then it would put a message onscreen "please enter search terms" or something.

Jose Cuervo posted:

I have a text file where each line has the following format

code:

X Y X Y X Y

where X is a 3 digit number and Y is a name (that can be more than just a single word), and the X and Y come in pairs (if there is an X there will be a Y. An example is:

code:

011  Anasco         129  San Lorenzo	069  Humacao

If I read the line in from a file, I would like to be able to split the line and extract the X Y pairs, but a regular split on white space will not work because of 'San Lorenzo'.

Any thoughts on how to accomplish this?

Dominoes posted:

Python code:

import re


text = '011  Anasco         129  San Lorenzo	069  Humacao'
x = re.findall('(\d{3})\s+([A-Z][a-z]+)\s+', text)

This gives you a list of tuples of the results. Note that this solution will have issues if the capitalization isn't like your examples.


Here's a breakdown of what that regex does:

• \d{3} matches any 3 digits together. The parentheses around it means to return that as part of the result.
  
• \s+ matches 1 or more spaces or line breaks
  
• [A-Za-z]+, from viking's example below, matches one or more letters together. Parentheses applies here too.
  

Dren posted:

Jose Cuervo, perhaps there are tabs between each of those X Y pairs? If so, parsing gets a lot easier because you can split on the tabs. e.g.

Python code:

# where 'line' has your input line in it
pairs = line.split('\t')
for pair in pairs:
    num = pair.split()[0]
    name = ' '.join(pair.split()[1:])

If not, this regex is a good starting point:

code:

\d+\s+[a-zA-Z\s]+

You can parse the line with almost the same code

Python code:

import re
# where 'line' has your input line in it
pairs = re.findall(r'\d+\s+[a-zA-Z\s]+', line)
for pair in pairs:
    num = pair.split()[0]
    name = ' '.join(pair.split()[1:])

Omnomnomnivore posted:

Anyone know if there's a more direct way to do a vectorized substring operation than numpy.char.find?

code:

>>> jerks = numpy.array(['butthead', 'poophead', 'fartbutt'])
>>> has_butt = numpy.char.find(jerks, 'butt') != -1
>>> has_butt
array([ True, False,  True], dtype=bool)

There doesn't seem to be a numpy method that will vectorize str.__contains__ directly, unless I'm missing something.

Jose Cuervo posted:

Unfortunately the file did not have tabs between the X Y pairs. I ended up using

Python code:

re.findall('(\d{3})\s+([A-Za-z\-\s]+)', line)

because some of the names were hyphenated. I then used the .strip() function to remove the excess white space from around the Y name. But you all pointing me in the direction of regular expressions was exactly what I needed. Thanks.

Classicist posted:

Here's one that doesn't require a .strip(), not that it's actually any better, but I couldn't resist a regex puzzle.

Python code:

In [61]: re.findall(r'(\d+)\s+(.+?)\s*(?=\d|$)', data)
Out[61]: [('011', 'Anasco'), ('129', 'San Lorenzo'), ('069', 'Humacao')]

Dren posted:

Lookaheads are cheating

Drone posted:

So I'm teaching myself Python after basically everyone recommended it to me as baby's first programming language, and I'm having a lot more fun with it than I ever thought I would. I've run through a couple beginner courses (Code Academy and another really great one that I seem to have lost the URL for, basically a tutorial for people who know nothing about programming). I'm supplementing what I'm learning there with some more "practical" hands-on stuff from Youtube, since I sometimes have a hard time learning something when I can't see the practical application of it.

Anyway, I've got a goal in mind for a learning project. Without getting into too much detail since I'm not sure I'll stick with it, it's a type of fairly simple trivia game. I set out with the basic goal of creating a trivia game that enables me to store a bank of easily-editable questions in a plaintext file (right now .txt, but I think a .csv would work better). The program would then pull the questions, in random order, from the question bank file.

Thankfully there are a billion tutorials for basic trivia games in Python, and I've run through several of them. One of them is pretty great, astoundingly simple, and even has my basic plaintext storage system worked out. I understand pretty much all of the following code and why it's used, with the exception of the critical "with" command, which makes the whole thing work:

code:

from random import shuffle

with open("questions.txt") as questionBank:
    lines = questionBank.readlines()

shuffle(lines)
numRight = 0
wrong = []

numQuestions = int(input("How many questions would you like to answer? "))

for line in lines[:numQuestions]:
    question, rightAnswer = line.strip().split("\t")
    answer = input(question + " ")
    if answer.lower() == rightAnswer.lower():
        print("Right!")
        numRight += 1
    else:
        print("Wrong! The answer is", rightAnswer)
        wrong.append(question)

print("You got %d right!" % (numRight))
if (wrong):
    print("You got these wrong: ")
    for q in wrong:
        print(q)

This question probably sounds really stupid, but considering I've only got a couple days of any kind of programming experience under my belt, it's probably a least a little cute Basically, can someone explain 'with' to me?

Other questions: if I wanted to use a different type of file (say, a .csv), how would I go about defining the 'question' and 'rightAnswer' variables instead of using line.strip().split("\t")?

Edit: note that excepting some minor changes in variable names, this is not my original code. Just a question I have from already-existing code.

Dominoes posted:

str(f.read())

post generator posted:

I 'm having fun taking it slowly and learning Python right away.

quote:

I am so fed up and farted , Bill Murray appeared and gave me something `` I can't edit the request headers they"

Lysidas posted:

What's f? Specifically, is it a file object opened in binary mode or text mode? Calling str on f.read() is at best a no-op if f is opened in text mode, and at worst it'll give you the wrong results if it's is opened in binary mode:

Python code:

>>> # simulate f.read() on a file opened with 'rb' mode
>>> b = b'some bytes \x80\x90\xa0\xb0\xc0\xd0\xe0\xf0'
>>> b
b'some bytes \x80\x90\xa0\xb0\xc0\xd0\xe0\xf0'
>>> str(b)
"b'some bytes \\x80\\x90\\xa0\\xb0\\xc0\\xd0\\xe0\\xf0'"

salisbury shake posted:

Has anyone used NLTK? It's py2k only, but suits my needs for funny text generation. Above was generated from a trigram model of this thread's last 50 pages.

Dominoes posted:

A file wrapper. It's bytes. Str() appears to work

SurgicalOntologist posted:

Does this have code smell?

Python code:

from contextlib import contextmanager


@contextmanager
def dummy_context():
   yield


user_context = dummy_context

# Allow user to supply different context


with user_context():
    # do stuff

I couldn't think of a way to enter a with statement only if the user wanted to. So instead I made a default with statement.

Dominoes posted:

Post more of the code. I guess it's code smell if you assume the rest of the code is also full of abstractions for the hell of it.

Jose Cuervo posted:

accipter posted:

Typically, I create multiple Python files that accomplish a small task. By the end of a project, I might have a dozen or so scripts the rely on the output from a couple different other scripts. I don't want to create one massive script because there are times when just one portion needs to be updated.

Do anyone have a method for keeping track of the dependencies like this? Perhaps a Make file would work, but I thought there might be a more pythonic solution.