hi, i have a small problem with a program that im writing. I have a table - stocks which contains information(products, barcodes etc.) about items stored in a fridge. I then have another table - shop which acts like a shop,containing loads of products and their barcodes.some of the products in the shop table are in the stock table at the...
I'm wondering, is it possible to make an sql query that does the same function as 'select products where barcode in table1 = barcode in table2'. I am writing this function in a python program. Once that function is called will the table be joined permanently or just while that function is running? thanks. lincoln. ...
Well I was reading this post and then I came across a code which was: jokes=range(1000000) domain=[(0,(len(jokes)*2)-i-1) for i in range(0,len(jokes)*2)] I thought wouldn't it be better to calculate the value of len(jokes) once outside the list comprehension? Well I tried it and timed three codes jv@Pioneer:~$ python -m timeit -s 'j...
I have a file called main.py and a file called classes.py main.py contains the application and what's happening while class.py contains some classes. main.py has the following code main.py import classes def addItem(text): print text myClass = classes.ExampleClass() And then we have classes.py classes.py class ExampleClass ...
hi, sorry for my previous question which was very ambiguous, but i think if i get the answer to this question I can work it out. In the program below i have selected the barcodes of products where the amount is less than the quantity. I want to say, that if the barcodes(in the fridge table) match barcodes in another table(products), set ...
After asking organising my Python project and then calling from a parent file in Python it's occurring to me that it'll be so much easier to put all my code in one file (data will be read in externally). I've always thought that this was bad project organisation but it seems to be the easiest way to deal with the problems I'm thinking I...
hi, does anyone know how to write a program in pytohn that will calculate the addition of the harmonic series. i.e.1/2 +1/3 +1/4... thanks. lincoln ...
I ran across this case of UnboundLocalError recently, which seems strange: import pprint def main(): if 'pprint' in globals(): print 'pprint is in globals()' pprint.pprint('Spam') from pprint import pprint pprint('Eggs') if __name__ == '__main__': main() Which produces: pprint is in globals() Traceback (most recent ...
I have an application that resides in a single .py file. I've been able to get pyInstaller to bundle it successfully into an EXE for Windows. The problem is, the application requires a .cfg file that always sits directly beside the application in the same directory. Normally, I build the path using the following code: import os confi...
How to return a list in Python??? When I tried returning a list,I got an empty list.What's the reason??? ...
I have the following file: abcde kwakwa <0x1A> line3 linllll Where <0x1A> represents a byte with the hex value of 0x1A. When attempting to read this file in Python as: for line in open('t.txt'): print line, It only reads the first two lines, and exits the loop. The solution seems to be to open the file in binary (or universal ...
All of the questions that I've asked recently about Python have been for this project. I have realised that the reason I'm asking so many questions may not be because I'm so new to Python (but I know a good bit of PHP) and is probably not because Python has some inherent flaw. Thus I will now say what the project is and what my current ...
Hi, I am a C++ developer, slowly getting into web development. I like LISP a lot but don't like AllegroCL and web-frameworks available for LISP. Which one is closer to LISP: Python or Ruby? I am looking for more freedom and ability to do cool hacks on language level. I don't consider tabs as a crime against nature. I can't seem to be a...
I am trying to write a life simulation in python with a variety of animals. It is impossible to name each instance of the classes I am going to use because I have no way of knowing how many there will be. So, my question: How can I automatically give a name to an object? I was thinking of creating a "Herd" class which could be all the...
I recall hearing that the connection process in mysql was designed to be very fast compared to other RDBMSes, and that therefore using a library that provides connection pooling (SQLAlchemy) won't actually help you that much if you enable the connection pool. Does anyone have any experience with this? I'm leery of enabling it because o...
Does anyone know anywhere there's a wide collection of python source code on the net with decent documentation? If so can someone post it up here, thanks. ...
Is there a built-in function/operator I could use to unpack values from a dictionary and assign it into instance variables? This is what I intend to do: c = MyClass() c.foo = 123 c.bar = 123 # c.foo == 123 and c.bar == 123 d = {'bar': 456} c.update(d) # c.foo == 123 and c.bar == 456 Something akin to dictionary update() which loa...
I am writing an application where one of the features is to allow the user to write an email template using Markdown syntax. Besides formatting, the user must be able to use placeholders for a couple of variables that would get replaced at runtime. The way this is currently working is very simple: the templates have the Pythonic %(var...
Using python 2.6 is there a way to check if all the items of a sequence equals a given value, in one statement? [pseudocode] my_sequence = (2,5,7,82,35) if all the values in (type(i) for i in my_sequence) == int: do() instead of, say: my_sequence = (2,5,7,82,35) all_int = True for i in my_sequence: if type(i) is not int: ...
Hello, I was just reading through "Learning Python" by Mark Lutz and came across this code sample: >>> L = ['grail'] >>> L.append(L) >>> L ['grail', [...]] It was identified as a cyclic data structure. So I was wondering, and here is my question: What is a 'cyclic data structure' used for in real life programming? There seems to...