Python - Dynamic PHP-like arrays

Question

I' trying to create a PHP like array in python. In Perl it would be a hash...

I want to organize content from the database in an array for easier access.

Something like:

myarray[db_numeric_value1][db_numeric_value2] = db_str_value

But no luck so far...

I tried to initialize myarray as an object list (myarray = {}) or as an array (myarray = [])... Also tried to initialize the "subarrays" but did not work either...

Thanks for your help!

Ron

see [this amazing answer](http://stackoverflow.com/a/8702435/989121) — georg, Jun 01 '12 at 08:09

score 2 · Accepted Answer · answered Jun 01 '12 at 08:42

2

you may use python's defaultdict with proper "default_factory":

from collections import defaultdict
myarray = defaultdict(dict)
myarray[4][5] = 34

answered Jun 01 '12 at 08:42

claperius

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Diego Navarro · Answer 2 · 2012-06-01T08:07:32.673

1

In Python it would be a dictionary (see python data structures)

In [4]: myarray = {3: {4: 'Hello World'}}

In [5]: myarray[3][4]
Out[5]: 'Hello World'

EDIT: the same thing but without initializing first

In [6]: myarray = {}
In [7]: myarray[3] = {}
In [9]: myarray[3][4] = 'Hello World'

In [10]: myarray[3][4]
Out[10]: 'Hello World'

Dictionary indexes can be also variables:

myarray[myindex] = myvalue

edited Jun 01 '12 at 08:07

answered Jun 01 '12 at 07:59

Diego Navarro

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AFAIK I tried to use a list when I initialized myarray with these brackets: []... When do this, Python tells me that my list index is out of range... The thing is that its a dynamical list so there should be no boundry, right? – Ron Jun 01 '12 at 08:03
Thanks for the code snippet...but how do I do this dynamically. The thing is that I dont know my values because I get them from my database... – Ron Jun 01 '12 at 08:05
Ok... I really think I'm missing something... When I try your static code it works just fine. As soon as I put a variable between the brackets he complains... the error is just the key. for example: myarray[val] = "foo" then the error is just val, ie. 3 – Ron Jun 01 '12 at 08:13
Show the **exact** code that fails, including all setup steps and the traceback. – Daniel Roseman Jun 01 '12 at 08:17
`myarray` always has to be a dictionary first: `myarray = {}` – Diego Navarro Jun 01 '12 at 08:18
i did this... but the other solution works just fine. nevertheless: thanks :) – Ron Jun 01 '12 at 08:23

Python - Dynamic PHP-like arrays

2 Answers2