+# searching 2 step feedback loop motives in OmniPath
+# using the web service data
+# note, this is the core PPI network
+# the fully literature curated "OmniPath sensu stricto"
+# it is possible to query the enzyme-substrate or the
+# transcriptional regulation datasets too:
+# 'http://omnipathdb.org/interactions?
+# 'datasets=omnipath,kinaseextra,tfregulons,mirnatarget'
+url = 'http://omnipathdb.org/interactions'
+ tuple(l.decode('ascii').strip().split('\t'))
+ urllib.request.urlopen(url).readlines()
+stimulation_rev = {tuple(reversed(s)) for s in stimulation}
+inhibition_rev = {tuple(reversed(i)) for i in inhibition}
+ (stimulation & inhibition_rev) |
+ (inhibition & stimulation_rev)
+dual_positive_1 = stimulation & stimulation_rev
+dual_positive_2 = inhibition & inhibition_rev
+len(dual_negative) # 426
+len(dual_positive_1) # 818
+len(dual_positive_2) # 154
