Search Results

Search found 13693 results on 548 pages for 'python metaprogramming'.

Page 122/548 | < Previous Page | 118 119 120 121 122 123 124 125 126 127 128 129  | Next Page >

  • Python unicode problem

    - by Somebody still uses you MS-DOS
    I'm receiving some data from a ZODB (Zope Object Database). I receive a mybrains object. Then I do: o = mybrains.getObject() and I receive a "Person" object in my project. Then, I can do b = o.name and doing print b on my class I get: José Carlos and print b.name.__class__ <type 'unicode'> I have a lot of "Person" objects. They are added to a list. names = [o.nome, o1.nome, o2.nome] Then, I trying to create a text file with this data. delimiter = ';' all = delimiter.join(names) + '\n' No problem. Now, when I do a print all I have: José Carlos;Jonas;Natália Juan;John But when I try to create a file of it: f = open("/tmp/test.txt", "w") f.write(all) I get an error like this (the positions aren't exaclty the same, since I change the names) UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 84: ordinal not in range(128) If I can print already with the "correct" form to display it, why I can't write a file with it? Which encode/decode method should I use to write a file with this data? I'm using Python 2.4.5 (can't upgrade it)

    Read the article

  • HTTPSConnection module missing in Python 2.6 on CentOS 5.2

    - by d2kagw
    Hi guys, I'm playing around with a Python application on CentOS 5.2. It uses the Boto module to communicate with Amazon Web Services, which requires communication through a HTTPS connection. When I try running my application I get an error regarding HTTPSConnection being missing: "AttributeError: 'module' object has no attribute 'HTTPSConnection'" Google doesn't really return anything relevant, I've tried most of the solutions but none of them solve the problem. Has anyone come across anything like it? Here's the traceback: Traceback (most recent call last): File "./chatter.py", line 114, in <module> sys.exit(main()) File "./chatter.py", line 92, in main chatter.status( ) File "/mnt/application/chatter/__init__.py", line 161, in status cQueue.connect() File "/mnt/application/chatter/tools.py", line 42, in connect self.connection = SQSConnection(cConfig.get("AWS", "KeyId"), cConfig.get("AWS", "AccessKey")); File "/usr/local/lib/python2.6/site-packages/boto-1.7a-py2.6.egg/boto/sqs/connection.py", line 54, in __init__ self.region.endpoint, debug, https_connection_factory) File "/usr/local/lib/python2.6/site-packages/boto-1.7a-py2.6.egg/boto/connection.py", line 418, in __init__ debug, https_connection_factory) File "/usr/local/lib/python2.6/site-packages/boto-1.7a-py2.6.egg/boto/connection.py", line 189, in __init__ self.refresh_http_connection(self.server, self.is_secure) File "/usr/local/lib/python2.6/site-packages/boto-1.7a-py2.6.egg/boto/connection.py", line 247, in refresh_http_connection connection = httplib.HTTPSConnection(host) AttributeError: 'module' object has no attribute 'HTTPSConnection'

    Read the article

  • Computing complex math equations in python

    - by dassouki
    Are there any libraries or techniques that simplify computing equations ? Take the following two examples: F = B * { [ a * b * sumOf (A / B ''' for all i ''' ) ] / [ sumOf(c * d * j) ] } where: F = cost from i to j B, a, b, c, d, j are all vectors in the format [ [zone_i, zone_j, cost_of_i_to_j], [..]] This should produce a vector F [ [1,2, F_1_2], ..., [i,j, F_i_j] ] T_ij = [ P_i * A_i * F_i_j] / [ SumOf [ Aj * F_i_j ] // j = 1 to j = n ] where: n is the number of zones T = vector [ [1, 2, A_1_2, P_1_2], ..., [i, j, A_i_j, P_i_j] ] F = vector [1, 2, F_1_2], ..., [i, j, F_i_j] so P_i would be the sum of all P_i_j for all j and Aj would be sum of all P_j for all i I'm not sure what I'm looking for, but perhaps a parser for these equations or methods to deal with multiple multiplications and products between vectors? To calculate some of the factors, for example A_j, this is what i use from collections import defaultdict A_j_dict = defaultdict(float) for A_item in TG: A_j_dict[A_item[1]] += A_item[3] Although this works fine, I really feel that it is a brute force / hacking method and unmaintainable in the case we want to add more variables or parameters. Are there any math equation parsers you'd recommend? Side Note: These equations are used to model travel. Currently I use excel to solve a lot of these equations; and I find that process to be daunting. I'd rather move to python where it pulls the data directly from our database (postgres) and outputs the results into the database. All that is figured out. I'm just struggling with evaluating the equations themselves. Thanks :)

    Read the article

  • Problem with python urllib

    - by mudder
    I'm getting an error when ever I try to pull down a web page with urllib.urlopen. I've disabled windows firewall and my AV so its not that. I can access the pages in my browser. I even reinstalled python to rule out it being a broken urllib. Any help would be greatly appreciated. >>> import urllib >>> h = urllib.urlopen("http://www.google.com").read() Traceback (most recent call last): File "<pyshell#1>", line 1, in <module> h = urllib.urlopen("http://www.google.com").read() File "C:\Python26\lib\urllib.py", line 86, in urlopen return opener.open(url) File "C:\Python26\lib\urllib.py", line 205, in open return getattr(self, name)(url) File "C:\Python26\lib\urllib.py", line 344, in open_http h.endheaders() File "C:\Python26\lib\httplib.py", line 904, in endheaders self._send_output() File "C:\Python26\lib\httplib.py", line 776, in _send_output self.send(msg) File "C:\Python26\lib\httplib.py", line 735, in send self.connect() File "C:\Python26\lib\httplib.py", line 716, in connect self.timeout) File "C:\Python26\lib\socket.py", line 514, in create_connection raise error, msg IOError: [Errno socket error] [Errno 10061] No connection could be made because the target machine actively refused it >>>

    Read the article

  • A better python property decorator

    - by leChuck
    I've inherited some python code that contains a rather cryptic decorator. This decorator sets properties in classes all over the project. The problem is that this I have traced my debugging problems to this decorator. Seems it "fubars" all debuggers I've tried and trying to speed up the code with psyco breaks everthing. (Seems psyco and this decorator dont play nice). I think it would be best to change it. def Property(function): """Allow readable properties""" keys = 'fget', 'fset', 'fdel' func_locals = {'doc':function.__doc__} def probeFunc(frame, event, arg): if event == 'return': locals = frame.f_locals func_locals.update(dict((k,locals.get(k)) for k in keys)) sys.settrace(None) return probeFunc sys.settrace(probeFunc) function() return property(**func_locals) Used like so: class A(object): @Property def prop(): def fget(self): return self.__prop def fset(self, value): self.__prop = value ... ect The errors I get say the problems are because of sys.settrace. (Perhaps this is abuse of settrace ?) My question: Is the same decorator achievable without sys.settrace. If not I'm in for some heavy rewrites.

    Read the article

  • Nicely representing a floating-point number in python

    - by dln385
    I want to represent a floating-point number as a string rounded to some number of significant digits, and never using the exponential format. Essentially, I want to display any floating-point number and make sure it “looks nice”. There are several parts to this problem: I need to be able to specify the number of significant digits. The number of significant digits needs to be variable, which can't be done with with the string formatting operator. I need it to be rounded the way a person would expect, not something like 1.999999999999 I've figured out one way of doing this, though it looks like a work-round and it's not quite perfect. (The maximum precision is 15 significant digits.) >>> def f(number, sigfig): return ("%.15f" % (round(number, int(-1 * floor(log10(number)) + (sigfig - 1))))).rstrip("0").rstrip(".") >>> print f(0.1, 1) 0.1 >>> print f(0.0000000000368568, 2) 0.000000000037 >>> print f(756867, 3) 757000 Is there a better way to do this? Why doesn't Python have a built-in function for this?

    Read the article

  • Parsing email with Python

    - by Manuel Ceron
    I'm writing a Python script to process emails returned from Procmail. As suggested in this question, I'm using the following Procmail config: :0: |$HOME/process_mail.py My process_mail.py script is receiving an email via stdin like this: From hostname Tue Jun 15 21:43:30 2010 Received: (qmail 8580 invoked from network); 15 Jun 2010 21:43:22 -0400 Received: from mail-fx0-f44.google.com (209.85.161.44) by ip-73-187-35-131.ip.secureserver.net with SMTP; 15 Jun 2010 21:43:22 -0400 Received: by fxm19 with SMTP id 19so170709fxm.3 for <[email protected]>; Tue, 15 Jun 2010 18:47:33 -0700 (PDT) MIME-Version: 1.0 Received: by 10.103.84.1 with SMTP id m1mr2774225mul.26.1276652853684; Tue, 15 Jun 2010 18:47:33 -0700 (PDT) Received: by 10.123.143.4 with HTTP; Tue, 15 Jun 2010 18:47:33 -0700 (PDT) Date: Tue, 15 Jun 2010 20:47:33 -0500 Message-ID: <[email protected]> Subject: TEST 12 From: Full Name <[email protected]> To: [email protected] Content-Type: text/plain; charset=ISO-8859-1 ONE TWO THREE I'm trying to parse the message in this way: >>> import email >>> msg = email.message_from_string(full_message) I want to get message fields like 'From', 'To' and 'Subject'. However, the message object does not contain any of these fields. What am I doing wrong?

    Read the article

  • Python print statement prints nothing with a carriage return

    - by Jonathan Sternberg
    I'm trying to write a simple tool that reads files from disc, does some image processing, and returns the result of the algorithm. Since the program can sometimes take awhile, I like to have a progress bar so I know where it is in the program. And since I don't like to clutter up my command line and I'm on a Unix platform, I wanted to use the '\r' character to print the progress bar on only one line. But when I have this code here, it prints nothing. # Files is a list with the filenames for i, f in enumerate(files): print '\r%d / %d' % (i, len(files)), # Code that takes a long time I have also tried: print '\r', i, '/', len(files), Now just to make sure this worked in python, I tried this: heartbeat = 1 while True: print '\rHello, world', heartbeat, heartbeat += 1 This code works perfectly. What's going on? My understanding of carriage returns on Linux was that it would just move the line feed character to the beginning and then I could overwrite old text that was written previously, as long as I don't print a newline anywhere. This doesn't seem to be happening though. Also, is there a better way to display a progress bar in a command line than what I'm current trying to do?

    Read the article

  • Radix Sort in Python [on hold]

    - by Steven Ramsey
    I could use some help. How would you write a program in python that implements a radix sort? Here is some info: A radix sort for base 10 integers is a based on sorting punch cards, but it turns out the sort is very ecient. The sort utilizes a main bin and 10 digit bins. Each bin acts like a queue and maintains its values in the order they arrive. The algorithm begins by placing each number in the main bin. Then it considers the ones digit for each value. The rst value is removed and placed in the digit bin corresponding to the ones digit. For example, 534 is placed in digit bin 4 and 662 is placed in the digit bin 2. Once all the values in the main bin are placed in the corresponding digit bin for ones, the values are collected from bin 0 to bin 9 (in that order) and placed back in the main bin. The process continues with the tens digit, the hundreds, and so on. After the last digit is processed, the main bin contains the values in order. Use randint, found in random, to create random integers from 1 to 100000. Use a list comphrension to create a list of varying sizes (10, 100, 1000, 10000, etc.). To use indexing to access the digits rst convert the integer to a string. For this sort to work, all numbers must have the same number of digits. To zero pad integers with leading zeros, use the string method str.zfill(). Once main bin is sorted, convert the strings back to integers. I'm not sure how to start this, Any help is appreciated. Thank you.

    Read the article

  • Python: Networked IDLE?

    - by Rosarch
    Is there any existing web app that lets multiple users work with an interactive IDLE type session at once? Something like: IDLE 2.6.4 Morgan: >>> letters = list("abcdefg") Morgan: >>> # now, how would you iterate over letters? Jack: >>> for char in letters: print "char %s" % char char a char b char c char d char e char f char g Morgan: >>> # nice nice If not, I would like to create one. Is there some module I can use that simulates an interactive session? I'd want an interface like this: def class InteractiveSession(): ''' An interactive Python session ''' def putLine(line): ''' Evaluates line ''' pass def outputLines(): ''' A list of all lines that have been output by the session ''' pass def currentVars(): ''' A dictionary of currently defined variables and their values ''' pass (Although that last function would be more of an extra feature.) To formulate my problem another way: I'd like to create a new front end for IDLE. How can I do this?

    Read the article

  • Python many-to-one mapping (creating equivalence classes)

    - by Adam Matan
    Hi, I have a project of converting one database to another. One of the original database columns defines the row's category. This coulmn should be mapepd to a new category in the new databse. For example, let's assume the original categories are:parrot, spam, cheese_shop, Cleese, Gilliam, Palin Now that's a little verbose for me, And I want to have these rows categorized as sketch, actor - That is, define all the sketches and all the actors as two equivalence classes. >>> monty={'parrot':'sketch', 'spam':'sketch', 'cheese_shop':'sketch', 'Cleese':'actor', 'Gilliam':'actor', 'Palin':'actor'} >>> monty {'Gilliam': 'actor', 'Cleese': 'actor', 'parrot': 'sketch', 'spam': 'sketch', 'Palin': 'actor', 'cheese_shop': 'sketch'} That's quite awkward- I would prefer having something like: monty={ ('parrot','spam','cheese_shop'): 'sketch', ('Cleese', 'Gilliam', 'Palin') : 'actors'} But this, of course, sets the entire tuple as a key: >>> monty['parrot'] Traceback (most recent call last): File "<pyshell#29>", line 1, in <module> monty['parrot'] KeyError: 'parrot' Any ideas how to create an elegant many-to-one dictionary in Python? Thanks, Adam

    Read the article

  • Python access an object byref / Need tagging

    - by Aaron C. de Bruyn
    I need to suck data from stdin and create a object. The incoming data is between 5 and 10 lines long. Each line has a process number and either an IP address or a hash. For example: pid=123 ip=192.168.0.1 - some data pid=123 hash=ABCDEF0123 - more data hash=ABCDEF123 - More data ip=192.168.0.1 - even more data I need to put this data into a class like: class MyData(): pid = None hash = None ip = None lines = [] I need to be able to look up the object by IP, HASH, or PID. The tough part is that there are multiple streams of data intermixed coming from stdin. (There could be hundreds or thousands of processes writing data at the same time.) I have regular expressions pulling out the PID, IP, and HASH that I need, but how can I access the object by any of those values? My thought was to do something like this: myarray = {} for each line in sys.stdin.readlines(): if pid and ip: #If we can get a PID out of the line myarray[pid] = MyData().pid = pid #Create a new MyData object, assign the PID, and stick it in myarray accessible by PID. myarray[pid].ip = ip #Add the IP address to the new object myarray[pid].lines.append(data) #Append the data myarray[ip] = myarray[pid] #Take the object by PID and create a key from the IP. <snip>do something similar for pid and hash, hash and ip, etc...</snip> This gives my an array with two keys (a PID and an IP) and they both point to the same object. But on the next iteration of the loop, if I find (for example) an IP and HASH and do: myarray[hash] = myarray[ip] The following is False: myarray[hash] == myarray[ip] Hopefully that was clear. I hate to admit that waaay back in the VB days, I remember being able handle objects byref instead of byval. Is there something similar in Python? Or am I just approaching this wrong?

    Read the article

  • reading csv files in scipy/numpy in Python

    - by user248237
    I am having trouble reading a csv file, delimited by tabs, in python. I use the following function: def csv2array(filename, skiprows=0, delimiter='\t', raw_header=False, missing=None, with_header=True): """ Parse a file name into an array. Return the array and additional header lines. By default, parse the header lines into dictionaries, assuming the parameters are numeric, using 'parse_header'. """ f = open(filename, 'r') skipped_rows = [] for n in range(skiprows): header_line = f.readline().strip() if raw_header: skipped_rows.append(header_line) else: skipped_rows.append(parse_header(header_line)) f.close() if missing: data = genfromtxt(filename, dtype=None, names=with_header, deletechars='', skiprows=skiprows, missing=missing) else: if delimiter != '\t': data = genfromtxt(filename, dtype=None, names=with_header, delimiter=delimiter, deletechars='', skiprows=skiprows) else: data = genfromtxt(filename, dtype=None, names=with_header, deletechars='', skiprows=skiprows) if data.ndim == 0: data = array([data.item()]) return (data, skipped_rows) the problem is that genfromtxt complains about my files, e.g. with the error: Line #27100 (got 12 columns instead of 16) I am not sure where these errors come from. Any ideas? Here's an example file that causes the problem: #Gene 120-1 120-3 120-4 30-1 30-3 30-4 C-1 C-2 C-5 genesymbol genedesc ENSMUSG00000000001 7.32 9.5 7.76 7.24 11.35 8.83 6.67 11.35 7.12 Gnai3 guanine nucleotide binding protein alpha ENSMUSG00000000003 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Pbsn probasin Is there a better way to write a generic csv2array function? thanks.

    Read the article

  • Figure out if element is present in multi-dimensional array in python

    - by Terje
    I am parsing a log containing nicknames and hostnames. I want to end up with an array that contains the hostname and the latest used nickname. I have the following code, which only creates a list over the hostnames: hostnames = [] # while(parsing): # nick = nick_on_current_line # host = host_on_current_line if host in hostnames: # Hostname is already present. pass else: # Hostname is not present hostnames.append(host) print hostnames # ['[email protected]', '[email protected]', '[email protected]'] I thought it would be nice to end up with something along the lines of the following: # [['[email protected]', 'John'], ['[email protected]', 'Mary'], ['[email protected]', 'Joe']] My problem is finding out if the hostname is present in such a list hostnames = [] # while(parsing): # nick = nick_on_current_line # host = host_on_current_line if host in hostnames[0]: # This doesn't work. # Hostname is already present. # Somehow check if the nick stored together # with the hostname is the latest one else: # Hostname is not present hostnames.append([host, nick]) Are there any easy fix to this, or should I try a different approach? I could always have an array with objects or structs (if there is such a thing in python), but I would prefer a solution to my array problem.

    Read the article

  • Python socket error on UDP data receive. (10054)

    - by Charles
    I currently have a problem using UDP and Python socket module. We have a server and clients. The problem occurs when we send data to a user. It's possible that user may have closed their connection to the server through a client crash, disconnect by ISP, or some other improper method. As such, it is possible to send data to a closed socket. Of course with UDP you can't tell if the data really reached or if it's closed, as it doesn't care (atleast, it doesn't bring up an exception). However, if you send data and it is closed off, you get data back somehow (???), which ends up giving you a socket error on sock.recvfrom. [Errno 10054] An existing connection was forcibly closed by the remote host. Almost seems like an automatic response from the connection. Although this is fine, and can be handled by a try: except: block (even if it lowers performance of the server a little bit). The problem is, I can't tell who this is coming from or what socket is closed. Is there anyway to find out 'who' (ip, socket #) sent this? It would be great as I could instantly just disconnect them and remove them from the data. Any suggestions? Thanks.

    Read the article

  • Quickly determine if a number is prime in Python for numbers < 1 billion

    - by Frór
    Hi, My current algorithm to check the primality of numbers in python is way to slow for numbers between 10 million and 1 billion. I want it to be improved knowing that I will never get numbers bigger than 1 billion. The context is that I can't get an implementation that is quick enough for solving problem 60 of project Euler: I'm getting the answer to the problem in 75 seconds where I need it in 60 seconds. http://projecteuler.net/index.php?section=problems&id=60 I have very few memory at my disposal so I can't store all the prime numbers below 1 billion. I'm currently using the standard trial division tuned with 6k±1. Is there anything better than this? Do I already need to get the Rabin-Miller method for numbers that are this large. primes_under_100 = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97] def isprime(n): if n <= 100: return n in primes_under_100 if n % 2 == 0 or n % 3 == 0: return False for f in range(5, int(n ** .5), 6): if n % f == 0 or n % (f + 2) == 0: return False return True How can I improve this algorithm?

    Read the article

  • Python multiprocessing doesn't play nicely with uuid.uuid4().

    - by yig
    I'm trying to generate a uuid for a filename, and I'm also using the multiprocessing module. Unpleasantly, all of my uuids end up exactly the same. Here is a small example: import multiprocessing import uuid def get_uuid( a ): ## Doesn't help to cycle through a bunch. #for i in xrange(10): uuid.uuid4() ## Doesn't help to reload the module. #reload( uuid ) ## Doesn't help to load it at the last minute. ## (I simultaneously comment out the module-level import). #import uuid ## uuid1() does work, but it differs only in the first 8 characters and includes identifying information about the computer. #return uuid.uuid1() return uuid.uuid4() def main(): pool = multiprocessing.Pool( 20 ) uuids = pool.map( get_uuid, range( 20 ) ) for id in uuids: print id if __name__ == '__main__': main() I peeked into uuid.py's code, and it seems to depending-on-the-platform use some OS-level routines for randomness, so I'm stumped as to a python-level solution (to do something like reload the uuid module or choose a new random seed). I could use uuid.uuid1(), but only 8 digits differ and I think there are derived exclusively from the time, which seems dangerous especially given that I'm multiprocessing (so the code could be executing at exactly the same time). Is there some Wisdom out there about this issue?

    Read the article

  • Reading numpy arrays outside of Python

    - by Abiel
    In a recent question I asked about the fastest way to convert a large numpy array to a delimited string. My reason for asking was because I wanted to take that plain text string and transmit it (over HTTP for instance) to clients written in other programming languages. A delimited string of numbers is obviously something that any client program can work with easily. However, it was suggested that because string conversion is slow, it would be faster on the Python side to do base64 encoding on the array and send it as binary. This is indeed faster. My question now is, (1) how can I make sure my encoded numpy array will travel well to clients on different operating systems and different hardware, and (2) how do I decode the binary data on the client side. For (1), my inclination is to do something like the following import numpy as np import base64 x = np.arange(100, dtype=np.float64) base64.b64encode(x.tostring()) Is there anything else I need to do? For (2), I would be happy to have an example in any programming language, where the goal is to take the numpy array of floats and turn them into a similar native data structure. Assume we have already done base64 decoding and have a byte array, and that we also know the numpy dtype, dimensions, and any other metadata which will be needed. Thanks.

    Read the article

  • Managing Instances in Python

    - by BeensTheGreat
    Hello, I am new to Python and this is my first time asking a stackOverflow question, but a long time reader. I am working on a simple card based game but am having trouble managing instances of my Hand class. If you look below you can see that the hand class is a simple container for cards(which are just int values) and each Player class contains a hand class. However, whenever I create multiple instances of my Player class they all seem to manipulate a single instance of the Hand class. From my experience in C and Java it seems that I am somehow making my Hand class static. If anyone could help with this problem I would appreciate it greatly. Thank you, Thad To clarify: An example of this situation would be p = player.Player() p1 = player.Player() p.recieveCard(15) p1.recieveCard(21) p.viewHand() which would result in: [15,21] even though only one card was added to p Hand class: class Hand: index = 0 cards = [] #Collections of cards #Constructor def __init__(self): self.index self.cards def addCard(self, card): """Adds a card to current hand""" self.cards.append(card) return card def discardCard(self, card): """Discards a card from current hand""" self.cards.remove(card) return card def viewCards(self): """Returns a collection of cards""" return self.cards def fold(self): """Folds the current hand""" temp = self.cards self.cards = [] return temp Player Class import hand class Player: name = "" position = 0 chips = 0 dealer = 0 pHand = [] def __init__ (self, nm, pos, buyIn, deal): self.name = nm self.position = pos self.chips = buyIn self.dealer = deal self.pHand = hand.Hand() return def recieveCard(self, card): """Recieve card from the dealer""" self.pHand.addCard(card) return card def discardCard(self, card): """Throw away a card""" self.pHand.discardCard(card) return card def viewHand(self): """View the players hand""" return self.pHand.viewCards() def getChips(self): """Get the number of chips the player currently holds""" return self.chips def setChips(self, chip): """Sets the number of chips the player holds""" self.chips = chip return def makeDealer(self): """Makes this player the dealer""" self.dealer = 1 return def notDealer(self): """Makes this player not the dealer""" self.dealer = 0 return def isDealer(self): """Returns flag wether this player is the dealer""" return self.dealer def getPosition(self): """Returns position of the player""" return self.position def getName(self): """Returns name of the player""" return self.name

    Read the article

  • Confused as to use a class or a function: Writing XML files using lxml and Python

    - by PulpFiction
    Hi. I need to write XML files using lxml and Python. However, I can't figure out whether to use a class to do this or a function. The point being, this is the first time I am developing a proper software and deciding where and why to use a class still seems mysterious. I will illustrate my point. For example, consider the following function based code I wrote for adding a subelement to a etree root. from lxml import etree root = etree.Element('document') def createSubElement(text, tagText = ""): etree.SubElement(root, text) # How do I do this: element.text = tagText createSubElement('firstChild') createSubElement('SecondChild') As expected, the output of this is: <document> <firstChild/> <SecondChild/> </document> However as you can notice the comment, I have no idea how to do set the text variable using this approach. Is using a class the only way to solve this? And if yes, can you give me some pointers on how to achieve this?

    Read the article

  • Database for Python Twisted

    - by Will
    There's an API for Twisted apps to talk to a database in a scalable way: twisted.enterprise.dbapi The confusing thing is, which database to pick? The database will have a Twisted app that is mostly making inserts and updates and relatively few selects, and then other strictly-read-only clients that are accessing the database directly making selects. (The read-only users are not necessarily selecting the data that the Twisted app is inserting; its not as though the database is being used as a message-queue) My understanding - which I'd like corrected/adviced - is that: Postgres is a great DB, but all the Python bindings - and there is a confusing maze of them - are abandonware There is psycopg2, but that makes a lot of noise about doing its own connection-pooling and things; does this co-exist gracefully/usefully/transparently with the Twisted async database connection pooling and such? SQLLite is a great database for little things but if used in a multi-user way it does whole-database locking, so performance would suck in the usage pattern I envisage MySQL - after the Oracle takeover, who'd want to adopt it now or adopt a fork? Is there anything else out there?

    Read the article

  • python mongokit Connection() AssertionError

    - by zalew
    just installed mongokit and can't figure out why I get AssertionError python console: >>> from mongokit import Connection >>> c = Connection() Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/local/lib/python2.6/dist-packages/mongokit-0.5.3-py2.6.egg/mongokit/connection.py", line 35, in __init__ super(Connection, self).__init__(*args, **kwargs) File "build/bdist.linux-i686/egg/pymongo/connection.py", line 169, in __init__ File "build/bdist.linux-i686/egg/pymongo/connection.py", line 338, in __find_master File "build/bdist.linux-i686/egg/pymongo/connection.py", line 226, in __master File "build/bdist.linux-i686/egg/pymongo/database.py", line 220, in command File "build/bdist.linux-i686/egg/pymongo/collection.py", line 356, in find_one File "build/bdist.linux-i686/egg/pymongo/cursor.py", line 485, in next File "build/bdist.linux-i686/egg/pymongo/cursor.py", line 461, in _refresh File "build/bdist.linux-i686/egg/pymongo/cursor.py", line 429, in __send_message File "build/bdist.linux-i686/egg/pymongo/helpers.py", line 98, in _unpack_response AssertionError >>> mongodb console: Wed Mar 31 10:27:34 connection accepted from 127.0.0.1:60480 #30 Wed Mar 31 10:27:34 end connection 127.0.0.1:60480 db 1.5 pymongo 1.5 (tested also on 1.4.) mongokit 0.5.3 (also 0.5.2)

    Read the article

  • Python: Catching / blocking SIGINT during system call

    - by danben
    I've written a web crawler that I'd like to be able to stop via the keyboard. I don't want the program to die when I interrupt it; it needs to flush its data to disk first. I also don't want to catch KeyboardInterruptedException, because the persistent data could be in an inconsistent state. My current solution is to define a signal handler that catches SIGINT and sets a flag; each iteration of the main loop checks this flag before processing the next url. However, I've found that if the system happens to be executing socket.recv() when I send the interrupt, I get this: ^C Interrupted; stopping... // indicates my interrupt handler ran Traceback (most recent call last): File "crawler_test.py", line 154, in <module> main() ... File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/socket.py", line 397, in readline data = recv(1) socket.error: [Errno 4] Interrupted system call and the process exits completely. Why does this happen? Is there a way I can prevent the interrupt from affecting the system call?

    Read the article

  • Multiple Unpacking Assignment in Python when you don't know the sequence length

    - by doug
    The textbook examples of multiple unpacking assignment are something like: import numpy as NP M = NP.arange(5) a, b, c, d, e = M # so of course, a = 0, b = 1, etc. M = NP.arange(20).reshape(5, 4) # numpy 5x4 array a, b, c, d, e = M # here, a = M[0,:], b = M[1,:], etc. (ie, a single row of M is assigned each to a through e) (My Q is not numpy specfic; indeed, i would prefer a pure python solution.) W/r/t the piece of code i'm looking at now, i see two complications on that straightforward scenario: i usually won't know the shape of M; and i want to unpack a certain number of items (definitely less than all items) and i want to put the remainder into a single container so back to the 5x4 array above, what i would very much like to be able to do is, for instance, assign the first three rows of M to a, b, and c respectively (exactly as above) and the rest of the rows (i have no idea how many there will be, just some positive integer) to a single container, all_the_rest = []. I'm not sure if i have explained this clearly; in any event, if i get feedback i'll promptly edit my Question.

    Read the article

  • Python IOError: Not a gzipped file (Gzip and Blowfish Encrypt/Compress)

    - by notbad.jpeg
    I'm having some problems with python's built-in library gzip. Looked through almost every other stack question about it, and none of them seem to work. MY PROBLEM IS THAT WHEN I TRY TO DECOMPRESS I GET THE IOError I'm Getting: Traceback (most recent call last): File "mymodule.py", line 61, in return gz.read() File "/usr/lib/python2.7/gzip.py", line 245, readself._read(readsize) File "/usr/lib/python2.7/gzip.py", line 287, in _readself._read_gzip_header() File "/usr/lib/python2.7/gzip.py", line 181, in _read_gzip_header raise IOError, 'Not a gzipped file'IOError: Not a gzipped file This is my code to send it over SMB, it might not make sense why i do things, but it's normally in a while loop and memory efficient, I just simplified it. buffer = cStringIO.StringIO(output) #output is from a subprocess call small_buffer = cStringIO.StringIO() small_string = buffer.read() #need a string to write to buffer gzip_obj = gzip.GzipFile(fileobj=small_buffer,compresslevel=6, mode='wb') gzip_obj.write(small_string) compressed_str = small_buffer.getvalue() blowfish = Blowfish.new('abcd', Blowfish.MODE_ECB) remainder = '|'*(8 - (len(compressed_str) % 8)) compressed_str += remainder encrypted = blowfish.encrypt(compressed_str) #i send it over smb, then retrieve it later Then this is the code that retrieves it: #buffer is a cStringIO object filled with data from smb retrieval decrypter = Blowfish.new('abcd', Blowfish.MODE_ECB) value = buffer.getvalue() decrypted = decrypter.decrypt(value) buff = cStringIO.StringIO(decrypted) buff.seek(0) gz = gzip.GzipFile(fileobj=buff) return gz.read() Here's the problem return gz.read()

    Read the article

< Previous Page | 118 119 120 121 122 123 124 125 126 127 128 129  | Next Page >