Search Results

Search found 15224 results on 609 pages for 'parallel python'.

Page 427/609 | < Previous Page | 423 424 425 426 427 428 429 430 431 432 433 434  | Next Page >

  • List filtering: list comprehension vs. lambda + filter

    - by Agos
    I happened to find myself having a basic filtering need: I have a list and I have to filter it by an attribute of the items. My code looked like this: list = [i for i in list if i.attribute == value] But then i thought, wouldn't it be better to write it like this? filter(lambda x: x.attribute == value, list) It's more readable, and if needed for performance the lambda could be taken out to gain something. Question is: are there any caveats in using the second way? Any performance difference? Am I missing the Pythonic Way™ entirely and should do it in yet another way (such as using itemgetter instead of the lambda)? Thanks in advance

    Read the article

  • Preventing a security breach

    - by Wiz
    I am creating a website where you "post", and the form content is saved in a MySql database, and upon loading the page, is retrieved, similar to facebook. I construct all the posts and insert raw html into a template. The thing is, as I was testing, I noticed that I could write javascript or other HTML into the form and submit it, and upon reloading, the html or JS would treated as source code, not a post. I figured that some simple encoding would do the trick, but using is not working. Is there an efficient way to prevent this type of security hole?

    Read the article

  • Writing a unique identifier to script?

    - by dannycab
    I'd like to write a subscript that adds a unique identifier (machine time) to a script everytime that it runs. However, each time I edit the script (in IDLE) the indetifiers are over-written. Is there a elegant way of doing this. The script that I wrote appears below. import os, time f = open('sys_time_append.py','r') lines = f.readlines() f.close() fout = open('sys_time_append.py','w') for thisline in lines: fout.write(thisline) fout.write('\n#'+str(time.time())+' s r\n') fout.close() Thanks for any help.

    Read the article

  • Find all A^x in a given range

    - by Austin Henley
    I need to find all monomials in the form AX that when evaluated falls within a range from m to n. It is safe to say that the base A is greater than 1, the power X is greater than 2, and only integers need to be used. For example, in the range 50 to 100, the solutions would be: 2^6 3^4 4^3 My first attempt to solve this was to brute force all combinations of A and X that make "sense." However this becomes too slow when used for very large numbers in a big range since these solutions are used in part of much more intensive processing. Here is the code: def monoSearch(min, max): base = 2 power = 3 while 1: while base**power < max: if base**power > min: print "Found " + repr(base) + "^" + repr(power) + " = " + repr(base**power) power = power + 1 base = base + 1 power = 3 if base**power > max: break I could remove one base**power by saving the value in a temporary variable but I don't think that would make a drastic effect. I also wondered if using logarithms would be better or if there was a closed form expression for this. I am open to any optimizations or alternatives to finding the solutions.

    Read the article

  • wxPython formatting questions

    - by Kevin
    I have an app I was working on to learn more about wxPython( I have been primarily been a scripter ). I forgot about it now I am opening it back up. It's a screen scraper, and I have it working almost the way I want it, going to build a regex parser to strip out the links in every scrape that I don't need. The questions I have are this. In it current state, if I check more than one site, it goes out and scrapes, and returns it in separate windows, the for:each section in the Clicked function. I want to put them in a frame, in the window, altogether. I also want to know if I can take the list they are read into and send it to a checklist, so someone could check off separate items, I want to build a save function and keep certain ones. In regards to a save function, I want to keep saved checks, are there calls to the widgets to save their states? I know it's a lot, but thanks for the help.

    Read the article

  • Defining the hash of an object as the sum of hashes of its members

    - by Space_C0wb0y
    I have a class that represents undirected edges in a graph. Every edge has two members vertex1 and vertex2 representing the vertices it connects. The problem is, that an edge can be specified two directions. My idea was now to define the hash of an edge as the sum of the hashes of its vertices. This way, the direction plays no role anymore, the hash would be the same. Are there any pitfalls with that?

    Read the article

  • nested list comprehension using intermediate result

    - by KentH
    I am trying to grok the output of a function which doesn't have the courtesy of setting a result code. I can tell it failed by the "error:" string which is mixed into the stderr stream, often in the middle of a different conversion status message. I have the following list comprehension which works, but scans for the "error:" string twice. Since it is only rescanning the actual error lines, it works fine, but it annoys me I can't figure out how to use a single scan. Here's the working code: errors = [e[e.find('error:'):] for e in err.splitlines() if 'error:' in e] The obvious (and wrong) way to simplify is to save the "find" result errors = [e[i:] for i in e.find('error:') if i != -1 for e in err.splitlines()] However, I get "UnboundLocalError: local variable 'e' referenced before assignment". Blindly reversing the 'for's in the comprehension also fails. How is this done? THanks. Kent

    Read the article

  • How do I assign functions in a dictionary?

    - by Ziv
    hi, I'm having a problem with a simple program I wrote, I want to perform a certain function according to the users input. I've already used a dictionary as a replacement for a switch to do assignment but when I try to assign functions to the dictionary it doesn't execute them... The code: def PrintValuesArea(): ## do this def PrintValuesLength(): ## do that def PrintValuesTime(): ## do third PrintTables={"a":PrintValuesArea,"l":PrintValuesLength,"t":PrintValuesTime} PrintTables.get(ans.lower()) ## ans is the user input what did I do wrong? It looks the same as all the examples I've seen....

    Read the article

  • Django & custom auth backend (web service) + no database. How to save stuff in session?

    - by Infinity
    I've been searching here and there, and based on this answer I've put together what you see below. It works, but I need to put some stuff in the user's session, right there inside authenticate. How would I store acme_token in the user's session, so that it will get cleared if they logged out? class AcmeUserBackend(object): # Create a User object if not already in the database? create_unknown_user = False def get_user(self, username): return AcmeUser(id=username) def authenticate(self, username=None, password=None): """ Check the username/password and return an AcmeUser. """ acme_token = ask_another_site_about_creds(username, password) if acme_token: return AcmeUser(id=username) return None ################## from django.contrib.auth.models import User class AcmeUser(User): objects = None # we cannot really use this w/o local DB def save(self): """saving to DB disabled""" pass def get_group_permissions(self): """If you don't make your own permissions module, the default also will use the DB. Throw it away""" return [] # likewise with the other permission defs def get_and_delete_messages(self): """Messages are stored in the DB. Darn!""" return []

    Read the article

  • Elegant way to add functionallity to previously defined functions

    - by Bastiaan
    How to combine two functions together I have a class controlling some hardware: class Heater() def set_power(self,dutycycle, period) ... def turn_on(self) ... def turn_off(self) And a class that connects to a database and handles all data logging fuctionallity for an experiment: class DataLogger() def __init__(self) # Record measurements and controls in a database def start(self,t) # Starts a new thread to aqcuire and reccord measuements every t secconds Now, in my program recipe.py I want to do something like: log = DataLogger() @DataLogger_decorator H1 = Heater() log.start(60) H1.set_power(10,100) H1.turn_on() sleep(10) H1.turn_off() etc Where all actions on H1 are recorded by the datalogger. I can change any of the classes involved, just looking for an elegant way to do this. Ideally the hardware functions remain separated from the database and DataLogger functions. And ideally the DataLogger is reusable for other controls and measurements.

    Read the article

  • a function that returns a random number that is a multiple of 3 between 0 and the function's non-negative integer parameter n

    - by martin
    I need to write a function called multipleOf3 that returns a random number that is a multiple of 3 between 0 and the function's non-negative integer parameter n and here is the result i want [Note: No number returned can be greater than the value of the parameter n] Examples: multipleOf3(0) -- 0 multipleOf3(1) -- 0 multipleOf3(2) -- 0 multipleOf3(3) -- 0 or 3 multipleOf3(20) -- 0 or 3 or 6 or 9 or 12 or 15 or 18

    Read the article

  • Sqlalchemy: Many to Many relationship error

    - by 1001010101
    Dear everyone, I am following the Many to many relationship described on http://www.sqlalchemy.org/docs/mappers.html#many-to-many #This is actually a VIEW tb_mapping_uGroups_uProducts = Table( 'mapping_uGroups_uProducts', metadata, Column('upID', Integer, ForeignKey('uProductsInfo.upID')), Column('ugID', Integer, ForeignKey('uGroupsInfo.ugID')) ) tb_uProducts = Table( 'uProductsInfo', metadata, Column('upID', Integer, primary_key=True) ) mapper( UnifiedProduct, tb_uProducts) tb_uGroupsInfo = Table( 'uGroupsInfo', metadata, Column('ugID', Integer, primary_key=True) ) mapper( UnifiedGroup, tb_uGroupsInfo, properties={ 'unifiedProducts': relation(UnifiedProduct, secondary=tb_mapping_uGroups_uProducts, backref="unifiedGroups") }) where the relationship between uProduct and uGroup are N:M. When I run the following sess.query(UnifiedProduct).join(UnifiedGroup).distinct()[:10] I am getting the error: sqlalchemy.exc.ArgumentError: Can't find any foreign key relationships between 'uProductsInfo' and 'uGroupsInfo' What am I doing wrong?

    Read the article

  • Aggregation over a few models - Django

    - by RadiantHex
    Hi folks, I'm trying to compute the average of a field over various subsets of a queryset. Player.objects.order_by('-score').filter(sex='male').aggregate(Avg('level')) This works perfectly! But... if I try to compute it for the top 50 players it does not work. Player.objects.order_by('-score').filter(sex='male')[:50].aggregate(Avg('level')) This last one returns the exact same result as the query above it, which is wrong. What am I doing wrong? Help would be very much appreciated!

    Read the article

  • command line arg?

    - by kaushik
    This is a module named XYZ. def func(x) ..... ..... if __name__=="__main__": print func(sys.argv[1]) Now I have imported this module in another code and want to use the func. How can i use it? import XYZ After this, where to give the argument, and syntax on how to call it, please?

    Read the article

  • does webapp has 'elseif' or 'elif' in template tags..

    - by zjm1126
    my code is : Hello!~~~ {% if user %} <p>Logged in as {{ user.first_name }} {{ user.last_name }}.</p> {% elif openid_user%} <p>Hello, {{openid_user.nickname}}! Do you want to <a href="{{openid_logout_url}}">Log out?</p> {% else %} <p><a href="/login?redirect={{ current_url }}">google Log in</a>.</p> <p><a href="/twitter">twitter Log in</a>.</p> <p><a href="/facebook">facebook Log in</a>.</p> <p><a href="{{openid_login_url}}">openid Log in</a>.</p> <iframe src="/_openid/login?continue=/"></iframe> {% endif %} the error is : TemplateSyntaxError: Invalid block tag: 'elif' does not webapp has a 'else if ' ? thanks

    Read the article

  • Object for storing strings geted from prints

    - by evg
    class MyWriter: def __init__(self, stdout): self.stdout = stdout self.dumps = [] def write(self, text): self.stdout.write(smart_unicode(text).encode('cp1251')) self.dumps.append(text) def close(self): self.stdout.close() writer = MyWriter(sys.stdout) save = sys.stdout sys.stdout = writer I use self.dumps list to store geted data from prints. Is it exists more convinient object for storing string lines in memory? ideally i want dump it to one big string. I can get it like this "\n".join(self.dumps) from code above. Mb it's better to just concat strings - self.dumps += text ?

    Read the article

  • How to merge or copy anonymous session data into user data when user logs in?

    - by benhoyt
    This is a general question, or perhaps a request for pointers to other open source projects to look at: I'm wondering how people merge an anonymous user's session data into the authenticated user data when a user logs in. For example, someone is browsing around your websites saving various items as favourites. He's not logged in, so they're saved to an anonymous user's data. Then he logs in, and we need to merge all that data into their (possibly existing) user data. Is this done different ways in an ad-hoc fashion for different applications? Or are there some best practices or other projects people can direct me to?

    Read the article

< Previous Page | 423 424 425 426 427 428 429 430 431 432 433 434  | Next Page >