import re
p = re.compile(ur'\b[0-9]{6}\b')
test_str = ur"C:\\Users\\416938\\AppData\\Roaming\\ESRI\\Desktop10.0\\ArcCatalog"
match = re.search(p, test_str)
if match:
print(match.group(0))
aW1wb3J0IHJlCnAgPSByZS5jb21waWxlKHVyJ1xiWzAtOV17Nn1cYicpCnRlc3Rfc3RyID0gdXIiQzpcXFVzZXJzXFw0MTY5MzhcXEFwcERhdGFcXFJvYW1pbmdcXEVTUklcXERlc2t0b3AxMC4wXFxBcmNDYXRhbG9nIgptYXRjaCA9IHJlLnNlYXJjaChwLCB0ZXN0X3N0cikKaWYgbWF0Y2g6CglwcmludChtYXRjaC5ncm91cCgwKSkKCQ==