Files
galaxy/tools/data_source/ucsc_tablebrowser.py
T
2008-06-04 13:02:15 +00:00

71 lines
2.1 KiB
Python

#!/usr/bin/env python
#Retreives data from UCSC and stores in a file. UCSC parameters are provided in the input/output file.
import urllib, sys, os, gzip, tempfile, shutil
from galaxy import eggs
from galaxy.datatypes import data
assert sys.version_info[:2] >= ( 2, 4 )
def stop_err( msg ):
sys.stderr.write( msg )
sys.exit()
def check_gzip( filename ):
temp = open( filename, "U" )
magic_check = temp.read( 2 )
temp.close()
if magic_check != data.gzip_magic:
return False
return True
def __main__():
filename = sys.argv[1]
params = {}
for line in open(filename, 'r'):
try:
line = line.strip()
fields = line.split('\t')
params[fields[0]] = fields[1]
except:
continue
URL = params.get( 'URL', None )
if not URL:
open( filename, 'w' ).write( "" )
#raise Exception('Datasource has not sent back a URL parameter')
stop_err( 'Datasource has not sent back a URL parameter.' )
out = open( filename, 'w' )
CHUNK_SIZE = 2**20 # 1Mb
try:
page = urllib.urlopen( URL, urllib.urlencode( params ) )
except:
stop_err( 'It appears that the UCSC Table Browser is currently offline. Please try again later.' )
while 1:
chunk = page.read( CHUNK_SIZE )
if not chunk:
break
out.write( chunk )
out.close()
if check_gzip( filename ):
fd, uncompressed = tempfile.mkstemp()
gzipped_file = gzip.GzipFile( filename )
while 1:
try:
chunk = gzipped_file.read( CHUNK_SIZE )
except IOError:
os.close( fd )
os.remove( uncompressed )
gzipped_file.close()
stop_err( 'Problem decompressing gzipped data, please try retrieving the data uncompressed.' )
if not chunk:
break
os.write( fd, chunk )
os.close( fd )
gzipped_file.close()
# Replace the gzipped file with the decompressed file
shutil.move( uncompressed, filename )
if __name__ == "__main__": __main__()