where function

[vorticitywolfe]

Is there a function in Python analogous to the "where" function in
IDL?

x=[0,1,2,3,4,2,8,9]
print where(x=2)

output:
[2,5]

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Re: where function

[vorticitywolfe]

On Mar 18, 10:48 pm, [EMAIL PROTECTED] wrote:
> vorticitywo:
>
> > Is there a function in Python analogous to the "where" function in
> > IDL?
>
> Python gives very elastic syntax, you can simply do:
>
> data = [0,1,2,3,4,2,8,9]
> print [pos for pos, el in enumerate(data) if el==2]
>
> Bye,
> bearophile

Thank you both, a little more cumbersome than I expected, but it does
the job! Thanks!

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Save time processing netcdf

[vorticitywolfe]

Hello,

I am working with a netcdf file and trying to remove a long string
from it e.g.
"KAST BLAH BLAH BLAH BLAH DATA BLAH DATA BLAH BLAH BLAH BLAH BLAH DATA
BLAH DATA BLAH"

Right now what I have works, but takes a long time to run... I think
this could be cut down to a quick 2 second run, but now takes around 5
minutes primarily because of the problem described below...

Why can't I use something like line 9 to get the entire string (which
returns [0], not
["KAST BLAH BLAH BLAH BLAH DATA BLAH DATA BLAH BLAH BLAH BLAH BLAH
DATA BLAH DATA BLAH"])? Rather I have to loop through it grabbing one
character at a time which drastically increases the processing time
and is very cumbersome.

Any one have any ideas or suggestions?


0 #OPEN NetCDF FILE TO READ
1   allDimNames=file.dimensions.keys()
2  max_string_length=file.dimensions['maxstringLen']
3   variableNames=file.variables.keys()
4   globalAttList=dir(file)
5   globalAttValue=getattr(file,'filePeriod')
6
7#GRABS DATA FROM STRING (2 DIMENSIONAL ARRAY) WITH THE CHARACTERS AS
INDIVIDUAL 8ELEMENTS
9   #YOU CAN'T JUST SPECIFY DATA VALUES 
DATA[0][0:max_string_length]
10  data=file.variables['rawstring'].getValue()
11  num_stations=data.shape
12  station_id=[str(mz)]
13
14  for m in station_id:
15  station_id=m
16  prec=[]
17  temps=[]
18
19  #Cycles through all of the stations in the file 
(LARGE ARRAY!!)
20  for k in range(num_stations[0]):
21  #Finds a certain station
22  if data[k][6]=='K' and 
data[k][7]==station_id[0:1] and data[k]
[8]==station_id[1:2] and 23data[k][9]==station_id[2:3] and data[k]
[15]=='5' or data[k][6]=='K' and data[k][7]==station_id[0:1] and
24data[k][8]==station_id[1:2] and data[k][9]==station_id[2:3] and
data[k][15]=='4':
25
26  #SEPARATES STRING 
CHARACTER BY CHARACTER ONLY WAY I'VE 27BEEN
ABLE TO FIGURE OUT HOW TO READ ENTIRE STRING INTO A STRING
28  for j in 
range(max_string_length):
29  
prec.append(str(data[k][j]))
30  S= ''.join(prec)
31  # # #   ##THEN RIP OFF THE 
WHITESPACE AT THE RIGHT OF THE
STRING
32  code=S.rstrip("\0")
33

Thanks for any of your help!

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