"""Utilities for extracting information from the ENCODE DCC
"""
+import logging
import urlparse
import urllib2
+LOGGER = logging.getLogger(__name__)
+
UCSCEncodePipeline = "http://encodesubmit.ucsc.edu/pipeline/"
+GOLDEN_PATHS = ["http://hgdownload-test.cse.ucsc.edu/goldenPath/"\
+ "{genome}/encodeDCC/{composite}/",
+ "http://hgdownload.cse.ucsc.edu/goldenPath/"\
+ "{genome}/encodeDCC/{composite}/"]
+
def ddf_download_url(submission_id):
"""Return url to download a DDF for a submission
return urlparse.urljoin(UCSCEncodePipeline, fragment)
-def get_ucsc_file_index(base_url):
+def get_encodedcc_file_index(genome, composite):
"""Get index of files for a ENCODE collection
+
+ returns None on error
"""
- if base_url[-1] != '/': base_url += '/'
- request = urllib2.urlopen(base_url + 'files.txt')
- file_index = parse_ucsc_file_index(request)
- return file_index
+ err = None
+ params = {'genome': genome,
+ 'composite': composite}
+
+ for path in GOLDEN_PATHS:
+ base_url = path.format(**params)
+ request_url = base_url + 'files.txt'
+
+ try:
+ request = urllib2.urlopen(request_url)
+ file_index = parse_ucsc_file_index(request, base_url)
+ return file_index
+ except urllib2.HTTPError, e:
+ err = e
+ pass
+
+ if err is not None:
+ errmsg = "get_ucsc_file_index <{0}>: {1}"
+ LOGGER.error(errmsg.format(request_url, str(e)))
+
+ return None
-def parse_ucsc_file_index(stream):
+def parse_ucsc_file_index(stream, base_url):
"""Turn a UCSC DCC files.txt index into a dictionary of name-value pairs
"""
file_index = {}
for line in stream:
filename, attribute_line = line.split('\t')
+ filename = base_url + filename
attributes = {}
for assignment in attribute_line.split(';'):
name, value = assignment.split('=')