sqlite3 version lacks instr

I have some queries that utilize instr wrapped by substr but the old version shipped in 2.7.5 doesn't have instr support. Has anyone encountered this and utilized other existing functions within the shipped 3.6.21 sqlite version to accomplish this? Thanks, jlc --

RE: sqlite3 version lacks instr

Has anyone encountered this and utilized other existing functions within the shipped 3.6.21 sqlite version to accomplish this? Sorry guys, forgot about create_function... -- http://mail.python.org/mailman/listinfo/python-list

Best practice for connections and cursors

I posted this to the sqlite list but I suspect there are more C oriented users on that list than Python, hopefully someone here can shed some light on this one. I have created a python module that I import within several other modules that simply opens a connection to an sqlite file and defines

Logging help

I have a couple handlers applied to a logger for a file and console destination. Default levels have been set for each, INFO+ to console and anything to file. How does one prevent logging.exception from going to a specific handler when it falls within the desired levels? Thanks, jlc --

RE: Best practice for connections and cursors

Speaking to the OP: personally, I don't like the approach of putting data access methods at the module level to begin with. I'd rather use a class. Just because it makes sense to have a singleton connection now doesn't mean it will always make sense as your application grows. In fact, the

RE: Logging help

Oh hai - as I was reading the documentation, look what I found: http://docs.python.org/2/library/logging.html#filter Methinks that should do exactly what you want. Hi Wayne, I was too hasty when I looked at filters as I didn't think they could do what I wanted. Turns out a logging object sent

RE: [argparse] mutually exclusive group with 2 sets of options

You can probably do something similar using sub commands (http://docs.python.org/2/library/argparse.html#sub-commands). The problem here is that argparse does not pass the subparser into the parsed args and shared args between subparsers need to be declared each time. Come execution time, when

RE: [argparse] mutually exclusive group with 2 sets of options

I think you are looking for exclusive groups: http://docs.python.org/2.7/library/argparse.html#argparse.add_mutually_excl usive_group No. That links first doc line in that method shows the very point we are all discussing: Create a mutually exclusive group. argparse will make sure that

RE: Running a command line program and reading the result as it runs

I'm using Python 2.7 under Windows and am trying to run a command line program and process the programs output as it is running. A number of web searches have indicated that the following code would work. import subprocess p = subprocess.Popen(D:\Python\Python27\Scripts\pip.exe list

sqlite issue in 2.7.5

I have been battling an issue hopefully someone here has insight with. I have a database with a few tables I perform a query against with some joins against columns collated with NOCASE that leverage = comparisons. Running the query on the database opened in sqlitestudio returns the results in

RE: sqlite issue in 2.7.5

This pragma speeds up most processes 10-20 times (yes 10-20): pragma synchronous=OFF See the SQLITE documentation for an explanation. I've found no problems with this setting. Aside from database integrity and consistency? :) I have that one set to OFF as my case mandates data processing and

Barcode printing

I need to convert a proprietary MS Access based printing solution into something I can maintain. Seems there is plenty available for generating barcodes in Python, so for the persons who have been down this road I was hoping to get a pointer or two. I need to create some type of output,

RE: Barcode printing

If that's a bit heavyweight (and confusing; it's not all free software, since some of it is under non-free license terms), there are other options. pyBarcode URL:http://pythonhosted.org/pyBarcode/ says it's a pure-Python library that takes a barcode type and the value, and generates an SVG of the

Logging timezones

The default converter attribute uses localtime, but often under windows when I add an additional logger, create a new file handler and set a formatter the time switches to utc. Obviously redefining a new converter class does nothing as the default is what I wanted to start with, localtime.

RE: Using with open(filename, 'ab'): and calling code only if the file is new?

with open(self.full_path, 'r') as input, open(self.output_csv, 'ab') as output: fieldnames = (...) csv_writer = DictWriter(output, filednames) # Call csv_writer.writeheader() if file is new. csv_writer.writerows(my_dict) I'm wondering what's the best

RE: Using with open(filename, 'ab'): and calling code only if the file is new?

Like Victor says, that opens him up to race conditions. Slim chance, it's no more possible than it happening in the time try/except takes to recover an alternative procedure. with open('in_file') as in_file, open('out_file', 'ab') as outfile_file: if os.path.getsize('out_file'):

RE: Compiling Python 3.3.2 on CentOS 6.4 - unable to find compiled OpenSSL?

Any thoughts on what we're doing wrong? Building them yourself:) Try iuscommunity.org for prebuilt packages... -- https://mail.python.org/mailman/listinfo/python-list

Robust regex

Trying to robustly parse a string that will have key/value pairs separated by three pipes, where each additional key/value (if more than one exists) will be delineated by four more pipes. string = 'key_1|||value_1key_2|||value_2' regex =

RE: Robust regex

Regexes may be overkill here. A simple string split might be better: Yup, and much more robust as I was looking for. Thanks everyone! jlc -- http://mail.python.org/mailman/listinfo/python-list

Dict comprehension help

I get a list of dicts as output from a source I need to then extract various dicts out of. I can easily extract the dict of choice based on it containing a key with a certain value using list comp but I was hoping to use dict comp so the output was not contained within a list. reduce(lambda

RE: Dict comprehension help

{k: v for d in my_list if d['key'] == value for (k, v) in d.items()} Ugh, had part of that backwards:) Nice! However, since you say that all dicts have a unique value for z['key'], you should never need to actually merge two dicts, correct? In that case, why not just use a plain for loop to

RE: Dict comprehension help

You could put the loop into a helper function, but if you are looping through the same my_list more than once why not build a lookup table my_dict = {d[key]: d for d in my_list} and then find the required dict with my_dict[value] I suppose, what I failed to clarify was that for each list of

Creating an iterator in a class

I am writing a class to provide a db backed configuration for an application. In my programs code, I import the class and pass the ODBC params to the class for its __init__ to instantiate a connection. I would like to create a function to generically access a table and provide an iterator. How

RE: Creating an iterator in a class

Have the method yield instead of returning: Thanks, that was simple, I was hung up on implementing magic methods. Thanks for the pointers guys! jlc -- http://mail.python.org/mailman/listinfo/python-list

RE: Creating an iterator in a class

It's probably best if you use separate cursors anyway. Say you have two methods with a shared cursor: def iter_table_a(self): self.cursor.execute(SELECT * FROM TABLE_A) yield from self.cursor def iter_table_b(self): self.cursor.execute(SELECT * FROM

Function Parameters

When you use optional named arguments in a function, how do you deal with with the incorrect assignment when only some args are supplied? If I do something like: def my_func(self, **kwargs): then handle the test cases with: if not kwargs.get('some_key'): raise SyntaxError or:

RE: Function Parameters

Don't use kwargs for this. List out the arguments in the function spec and give the optional ones reasonable defaults. I only use kwargs myself when the set of possible arguments is dynamic or unknown. Gotch ya, but when the inputs to some keywords are similar, if the function is called

Data structure question

I have a need for a script to hold several tuples with three values, two text strings and a lambda. I need to index the tuple based on either of the two strings. Normally a database would be ideal but for a self-contained script that's a bit much. Before I re-invent the wheel, are there any

RE: Data structure question

Not entirely sure I understand you, can you post an example? If what you mean is that you need to locate the function (lambda) when you know its corresponding strings, a dict will suit you just fine. Either maintain two dicts for the two separate strings (eg if they're name and location and

RE: Data structure question

How about two dictionaries, each containing the same tuples for values? If you create a tuple first, then add it to both dicts, you won't have any space-wasting duplicates. Thanks guys. -- https://mail.python.org/mailman/listinfo/python-list

Formatting text in a table with reportlab

I sent off a msg to the reportlab list but didn't find an answer, hoping someone here might have come across this... I am generating a table to hold text oriented by the specification of the label it gets printed on. I need to compress the vertical size of the table a little more but the larger

Unit tests and coverage

I have a script that accepts cmdline arguments and receives input via stdin. I have a unit test for it that uses Popen to setup an environment, pass the args and provide the stdin. Problem is obviously this does nothing for providing coverage. Given the above specifics, anyone know of a way to

RE: Unit tests and coverage

So, back to my original question; what do you mean by providing coverage? Hi Roy, I meant touch every line, such as what https://pypi.python.org/pypi/coverage measures. As the script is being invoked with Popen, I lose that luxury and only gain the assertions tests but that of course doesn't

RE: Unit tests and coverage

As the script is being invoked with Popen, I lose that luxury and only gain the assertions tests but that of course doesn't show me untested branches. Should have read the docs more thoroughly, works quite nice. jlc -- https://mail.python.org/mailman/listinfo/python-list

Argparse class method based instantiation

I have an Python3 argparse implementation that is invoked as a method from an imported class within a users script __main__. When argparse is setup in __main__ instead, all the help switches produce help then exit. When a help switch is passed based on the above implementation, they are

Implementing append within a descriptor

I have a caching non data descriptor that stores values in the implementing class instances __dict__. Something like: class Descriptor: def __init__(self, func, name=None, doc=None): self.__name__ = name or func.__name__ self.__module__ = func.__module__ self.__doc__

RE: Implementing append within a descriptor

You're going to have to subclass list if you want to intercept its methods. As I see it, there are two ways you could do that: when it's set, or when it's retrieved. I'd be inclined to do it in __set__, but either could work. In theory, you could make it practically invisible - just check to

RE: SQLite + FTS (full text search)

But on Windows when I use the official Python 3.3 32-bit binary from www.python.org this is not enabled. For an unobtrusive way [1] to gain this, see apsw. For what it's worth, I prefer this package over the built in module. Python 3.3.3 (v3.3.3:c3896275c0f6, Nov 18 2013, 21:19:30) [MSC

Documenting descriptors

I am documenting a few classes with Sphinx that utilize methods decorated with custom descriptors. These properties return data when called and Sphinx is content with a :returns: and :rtype: markup in the properties doc string. They also accept input, but parameter (not really applicable) nor var

Logging from a multiprocess application

I have a module that has one operation that benefits greatly from being multiprocessed. Its a console based module and as such I have a stream handler and filter associated to the console, obviously the mp based instances need special handling, so I have been experimenting with a socket server

RE: Logging from a multiprocess application

Maybe check out logstash (http://logstash.net/). That looks pretty slick, I am constrained to using something provided by the packaged modules in this scenario. I think I have it pretty close except for the fact that the LogRecordStreamHandler from the cookbook excepts when the sending

Unitest mock issue

I am trying to patch a method of a class thats proving to be less than trivial. The module I am writing a test for, ModuleA imports another ModuleB and instantiates a class from this. Problem is, ModuleA incorporates multiprocessing queues and I suspect I am missing the patch as the object in

Descriptor type hinting

How does one satisfy a lint/type checker with the return value of a class method decorated with a descriptor? It returns a dict, and I want the type hinting to suggest this versus the str|unknown its defaults to. Thanks, jlc -- https://mail.python.org/mailman/listinfo/python-list

RE: Descriptor type hinting

Surely the answer will depend on the linter you are using. Care to tell us, or shall we guess? Hey Steven, I am using PyCharm, I have to admit I feel silly on this one. I had a buried assignment that overrode the inferred type. It wasn't until a fresh set of eyes confirmed something was awry

asyncio question

I have a portion of code I need to speed up, there are 3 api calls to an external system where the first enumerates a large collection of objects I then loop through and perform two additional api calls each. The first call is instant, the second and third per object are very slow. Currently

RE: writing reading from a csv or txt file

Hi I have 3 csv files with a list of 5 items in each. rainfall in mm, duration time,time of day,wind speed, date. I am trying to compare the files. cutting out items in list list. ie:- first file (rainfall2012.csv)rainfall, duration,time of day,wind speed,date. first file

Soap list and soap users on this list

Seems the soap list is a little quiet and the moderator is mia regardless. Are there many soap users on this list familiar with Spyne or does anyone know the most optimal place to post such questions? Thanks! jlc -- https://mail.python.org/mailman/listinfo/python-list

RE: Soap list and soap users on this list

Is your question regarding anything at all Python, or are you just looking for helpful nerds? :) Hi Chris, Thanks for responding. I've been looking at Spyne to produce a service that can accept a request formatted as follows: ?xml version='1.0' encoding='UTF-8'? SOAP-ENV:Envelope

RE: Soap list and soap users on this list

Read first. You can try : http://spyne.io/docs/2.10/ https://pythonhosted.org/Soapbox/ Thanks Marcus, I assure you I have been reading but missed soapbox, I'll keep hacking away, thanks for the pointer. jlc -- https://mail.python.org/mailman/listinfo/python-list

RE: Executing pl/sql script File in python without sqlclient

Is there a way to execute pl/sql Script files through Python without sqlclient. https://code.google.com/p/pypyodbc/ might work for you... i have checked cx_oracle and i guess it requires oracle client, so is there a way to execute without oracle client. Right, as the name implies it uses

RE: Soap list and soap users on this list

https://gist.github.com/plq/11384113 Unfortunately, you need the latest Spyne from https://github.com/arskom/spyne, this doesn't work with 2.10 2.11 is due around end of may, beginning of june. Ping back if you got any other questions. Burak, Thanks a ton! I've just pulled this down

RE: Designing a network in Python

I have managed to read most of the important data in the xml onto lists. Now, I have two lists, Source and Destination and I'd like to create bi-directional links between them. And moreover, I'd like to assign some kind of a bandwidth capacity to the links and similarly, storage and

RE: Designing a network in Python

I don't know how to do that stuff in python. Basically, I'm trying to pull certain data from the xml file like the node-name, source, destination and the capacity. Since, I am done with that part, I now want to have a link between source and destination and assign capacity to it. I dont

Exception problem with module

I am working with a module that I am seeing some odd behavior. A module.foo builds a custom exception, module.foo.MyError, its done right afaict. Another module, module.bar imports this and calls bar.__setattr__('a_new_name', MyError). Now, not in all but in some cases when I catch a_new_name,

RE: Exception problem with module

Best would be to print out what's in a_new_name to see if it really is what you think it is. If you think it is what you think it is, have a look at its __mro__ (method resolution order, it's an attribute of every class), to see what it's really inheriting. That should show you what's

RE: Exception problem with module

I see that you've solved your immediate problem, but you shouldn't call __setattr__ directly. That should actually be written setattr(bar, 'a_new_name', MyError) But really, since bar is (apparently) a module, and it is *bar itself* setting the attribute, the better way is

Re: Problem building 3.5 on Windows

Mark, Excuse the format of this post, stuck on the road only with an iPhone but in the event it helps, http://blog.vrplumber.com/b/2014/02/12/step-2-get-amd64-compatible-vs-2010/ may be useful. Jlc -- https://mail.python.org/mailman/listinfo/python-list

RE: Exception problem with module

Well I am not sure what advantage this has for the user, not my code as I don't advocate the import to begin with it, its fine spelled as it was from where it was... The advantage for the user is: /snip Hey Steven, Sorry for the late reply (travelling). My comment wasn't clear, I was

RE: compiled cx_freeze

Anyone knows where to get a compiled cx_freeze that has already has this patch? http://www.lfd.uci.edu/~gohlke/pythonlibs/#cx_freeze -- https://mail.python.org/mailman/listinfo/python-list

RE: compiled cx_freeze

Unfortunately, this is buggy too. Here is a test output from a compiled console exe created with the above version of cx freeze: Let Christoph know, he is very responsive and extremely helpful. -- https://mail.python.org/mailman/listinfo/python-list

Using pyVmomi

I am doing some scripting with pyVmomi under 2.6.8 so the code may run directly on a vmware esxi server. As the code is long running, it surpasses the authentication timeout. For anyone familiar with this code and/or this style of programming, does anyone have a recommendation for an elegant

RE: Using pyVmomi

You could: - have a single point of entry that can check and, if necessary, revalidate - create a helper that checks and, if necessary, revalidate, which is then called where ever needed - create a decorator that does the above for each function that needs it Hi Ethan,

RE: GIL detector

I don't have to care about threading issues all the time and can otherwise freely choose the right model of parallelism that suits my current use case when the need arises (and threads are rarely the right model). I'm sure that's not just me. The sound bite of a loyal Python coder:) If it

Processing xml for output with cElementTree

I am unfortunately unable to use lxml for a project and must resort to base only libraries to create several nested elements located directly under a root element. The caveat is the incremental writing and flushing of the nested elements as they are created. So assuming the structure is

RE: Using map()

I checked my modules with pylint and saw the following warning: W: 25,29: Used builtin function 'map' (bad-builtin) Why is the use of map() discouraged? It' such a useful thing. The warning manifests from the opinion that a comprehension is more suitable. You can disable the warning or you

Numpy outlier removal

I have a dataset that consists of a dict with text descriptions and values that are integers. If required, I collect the values into a list and create a numpy array running it through a simple routine: data[abs(data - mean(data)) m * std(data)] where m is the number of std deviations to

RE: Numpy outlier removal

Assuming your data and the dictionary are keyed by a common set of keys:  for key in descriptions:    if abs(data[key] - mean(data)) = m * std(data):        del data[key]        del descriptions[key] Heh, yeah sometimes the obvious is too simple to see. I used a dict comp to rebuild the

RE: Numpy outlier removal

In other words: this approach for detecting outliers is nothing more than  a very rough, and very bad, heuristic, and should be avoided. Heh, very true but the results will only be used for conversational purposes. I am making an assumption that the data is normally distributed and I do expect

Dict comp help

Hi, Slightly different take on an old problem, I have a list of dicts, I need to build one dict from this based on two values from each dict in the list. Each of the dicts in the list have similar key names, but values of course differ. [{'a': 'xx', 'b': 'yy', 'c': 'zz'},  {'a': 'dd', 'b':

RE: Dict comp help

data = [{'a': 'xx', 'b': 'yy', 'c': 'zz'},  {'a': 'dd', 'b': 'ee', 'c':  'ff'}]  {d[a]: d[c] for d in data} {'xx': 'zz', 'dd': 'ff'} Priceless, That is exactly what I needed, for which I certainly over complicated! Thanks everyone! jlc --

Logging within a class

Within __init__ I setup a log with self.log = logging.getLogger('foo') then add a console and filehandler which requires the formatting to be specified. There a few methods I setup a local log object by calling getChild against the global log object. This works fine until I need to adjust the 

A better way to accomplish loop

I have an issue with some code I have been passed: for (x, y) in [(a_dict1, a_tuple[0]), (a_dict2, a_tuple[1])]: I only noticed it as PyCharm failed to assign the str type to y, whereas it knew the tuples 0 and 1 item were type str. In the loop it flags the passing of y into a method that

RE: A better way to accomplish loop

I think you're saying that the lint-feature of PyCharm is trying to  guess the object types, and telling you there's a conflict here.  I don't think you're saying that it executes incorrectly. Hah, yeah sorry Dave that's it.  Still there are ways to express it differently, and maybe one of

Switch statement

I have a switch statement composed using a dict: switch = {     'a': func_a,     'b': func_b,     'c': func_c } switch.get(var, default)() As a result of multiple functions per choice, it migrated to: switch = {     'a': (func_a1, func_a2),     'b': (func_b1, func_b2),     'c': (func_c, ) }

RE: Switch statement

switch = {  'A': functools.partial(spam, a), 'B': lambda b, c=c: ham(b, c), 'C': eggs, }    switch[letter](b) That's cool, never even thought to use lambdas. functools.partial isn't always applicable, but when it is, you should  prefer it over lambda since it will be very

RE: Switch statement

Or could you do something like: arguments_to_pass = [list of some sort] switch.get(var, default)(*arguments_to_pass) Stevens lambda suggestion was most appropriate. Within the switch, there are functions called with none, or some variation of arguments. It was not easy to pass them in after

Decorator help

I have a class which sets up some class vars, then several methods that are passed in data and do work referencing the class vars. I want to decorate these methods, the decorator needs access to the class vars, so I thought about making the decorator its own class and allowing it to accept

RE: Decorator help

 So decorators will never take instance variables as arguments (nor should they, since no instance can possibly exist when they execute). Right, I never thought of it that way, my only use of them has been trivial, in non class scenarios so far. Bear in mind, a decorator should take a

RE: Decorator help

When you say class vars, do you mean variables which hold classes? You guessed correctly, and thanks for pointing out the ambiguity in my references. The one doesn't follow from the other. Writing decorators as classes is   fairly unusual. Normally, they will be regular functions. I see,

Case insensitive dict

I was doing some work with the ldap module and required a ci dict that was case insensitive but case preserving. It turned out the cidict class they implemented was broken with respect to pop, it is inherited and not re implemented to work. Before I set about re-inventing the wheel, anyone know

Ldap module and base64 oncoding

I have some data I am working with that is not being interpreted as a string requiring base64 encoding when sent to the ldif module for output. The base64 string parsed is ZGV0XDMzMTB3YmJccGc= and the raw string is det\3310wbb\pg. I'll admit my understanding of the handling requirements of non

RE: Ldap module and base64 oncoding

Can you give an example of the code you have? I actually just overrode the regex used by the method in the LDIFWriter class to be far more broad about what it interprets as a safe string. I really need to properly handle reading, manipulating and writing non ascii data to solve this... Shame

RE: authentication with python-ldap

I have been doing the same thing and I tried to use java for testing the credentials and they are correct. It works perfectly with java. I really don´t know what we´re doing wrong. You are accessing a protected operation of the LDAP server and it (the server) rejects it due to invalid

RE: Ldap module and base64 oncoding

I'm not sure what exactly you're asking for. Especially is not being interpreted as a string requiring base64 encoding is written without giving the right context. So I'm just guessing that this might be the usual misunderstandings with use of base64 in LDIF. Read more about when LDIF

RE: Ldap module and base64 oncoding

Hi Michael, Processing LDIF is one thing, doing LDAP operations another. LDIF itself is meant to be ASCII-clean. But each attribute value can carry any byte sequence (e.g. attribute 'jpegPhoto'). There's no further processing by module LDIF - it simply returns byte sequences. The access

RE: Ldap module and base64 oncoding

Note that all modules in python-ldap up to 2.4.10 including module 'ldif' expect raw byte strings to be passed as arguments. It seems to me you're passing a Unicode object in the entry dictionary which will fail in case an attribute value contains NON-ASCII chars. Yup, I was. python-ldap

Popen and reading stdout in windows

I have a use where writing an interim file is not convenient and I was hoping to iterate through maybe 100k lines of output by a process as its generated or roughly anyways. Seems to be a common question on ST, and more easily solved in Linux. Anyone currently doing this with Python 2.7 in

RE: Popen and reading stdout in windows

You leave out an awful amount of detail. I have no idea what ST is, so I'll have to guess your real problem. Ugh, sorry guys its been one of those days, the post was rather useless... I am using Popen to run the exe with communicate() and I have sent stdout to PIPE without luck. Just not

Popen in Python3

I am trying to invoke a binary that requires dll's in two places all of which are included in the path env variable in windows. When running this binary with popen it can not find either, passing env=os.environ to open made no difference. Anyone know what might cause this or how to work around

Decorator help

I have a set of methods which take args that I decorate twice, def wrapped(func): def wrap(*args, **kwargs): try: val = func(*args, **kwargs) # some work except BaseException as error: log.exception(error) return [] return

RE: Decorator help

If you don't want to do that, you'd need to use introspection of a remarkably hacky sort. If you want that, well, it'll take a mo. After some effort I'm pretty confident that the hacky way is impossible. Hah, I fired it in PyCharm's debugger and spent a wack time myself, thanks for the

RE: Decorator help

Well, technically it's func.func_closure[0].cell_contents.__name__ but of course you cannot know that for the general case. Hah, I admit I lacked perseverance in looking at this in PyCharms debugger as I missed that. Much appreciated! jlc --

List comp help

I have a dict of lists. I need to create a list of 2 tuples, where each tuple is a key from the dict with one of the keys list items. my_dict = { 'key_a': ['val_a', 'val_b'], 'key_b': ['val_c'], 'key_c': [] } [(k, x) for k, v in my_dict.items() for x in v] This works, but I need to

RE: List comp help

Yeah, it's remarkably easy too! Try this: [(k, x) for k, v in my_dict.items() for x in v or [None]] An empty list counts as false, so the 'or' will then take the second option, and iterate over the one-item list with None in it. Right, I overlooked that! Much appreciated, jlc --

ORM opinion

Begrudgingly, I need to migrate away from SQLAlchemy onto a package that has fast imports and very fast model build times. I have a less than ideal application that uses Python as a plugin interpreter which is not performant in this use case where its being invoked freshly several times per

RE: ORM opinion

First recommendation: Less layers. Instead of SQLAlchemy, just import sqlite3 and use it directly. You should be able to switch out import sqlite as db for import psycopg2 as db or any other Python DB API module, and still have most/all of the benefit of the extra layer, without any extra

RE: ORM opinion

Anything listed here http://www.pythoncentral.io/sqlalchemy-vs-orms/ you've not heard about? I found peewee easy to use although I've clearly no idea if it suits your needs. There's only one way to find out :) Hi Mark, I found that article before posting and some of the guys here have

Hashed lookups for tabular data

I have some tabular data for example 3 tuples that I need to build a container for where lookups into any one of the three fields are O(1). Does something in the base library exist, or if not is there an efficient implementation of such a container that has been implemented before I give it a go?

Re: Hashed lookups for tabular data

So presumably your data's small enough to fit into memory, right? If it isn't, going back to the database every time would be the best option. But if it is, can you simply keep three dictionaries in sync? Hi Chris, Yeah the data can fit in memory and hence the desire to avoid a trip here.

Re: Hashed lookups for tabular data

Why not take a look at pandas as see if there's anything there you could use? Excellent docs here http://pandas.pydata.org/pandas-docs/stable/ and the mailing list is available at gmane.comp.python.pydata amongst other places. Mark, Actually it was the first thing that came to mind. I did

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