[Tutor] Help for Python Beginner with extracting and manipulating data from thousands of ASCII files
Alan Gauld
alan.gauld at btinternet.com
Mon Oct 1 01:33:44 CEST 2012
On 30/09/12 23:07, Cecilia Chavana-Bryant wrote:
> Hola again Python Tutor!
>
> With a friend's help I have the following code to extract reflectance
> data from an ASCII data file, do a bit of data manipulation to calibrate
> the data and then write the calibrated file into an out file.
<snip>
> I have successfully calibrated one ASCII file at a time with this code.
> However, I have 1,000s of files that I need to calibrate so I would like
> some help to modify this code so it can:
>
> 1. Use one calibration file (Cal_FileP17.txt) on data files created from
> July to the 18th Sep and a different calibration file (Cal_FileP19.txt)
> for data files created from the 19th of Sep onwards.
>
> 2. Find all the .txt files in a folder called ASCII_files, which is
> subdivided into 12 different folders and calibrate all these files
Number 2 is easier to solve and the os.walk() and glob.glob()
functions should provide all the tools you need.
Number 1 is more tricky since there is no obvious way to determine the
arbitrary start/stop dates you specify. So I'd suggest you need to
generalise the requirement to take a start/stop date as well as the
calibration file name and the input data file pattern. Use those as
input parameters to a function that generates the list of files to
process and then calls your existing code (wrapped in a new function)
and possibly provide default values for all/some of the parameters.
Another option is to add the start/end dates to the calibration file if
you have control of that, but personally I'd stick with input parameters...
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
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