import re
s = "myserver://password,123@ip:port/key1,myserver://pass2@ip2:port2/key2"
rx1 = r'\s*,?\s*myserver://'
res1 = filter(None, re.split(rx1, s))
print(res1)
#or
rx2 = r"myserver://(.*?)(?=\s*,\s*myserver://|$)"
res2 = re.findall(rx2, s)
print(res2)
aW1wb3J0IHJlCgpzID0gIm15c2VydmVyOi8vcGFzc3dvcmQsMTIzQGlwOnBvcnQva2V5MSxteXNlcnZlcjovL3Bhc3MyQGlwMjpwb3J0Mi9rZXkyIgoKcngxID0gcidccyosP1xzKm15c2VydmVyOi8vJwpyZXMxID0gZmlsdGVyKE5vbmUsIHJlLnNwbGl0KHJ4MSwgcykpCnByaW50KHJlczEpCgojb3IKcngyID0gciJteXNlcnZlcjovLyguKj8pKD89XHMqLFxzKm15c2VydmVyOi8vfCQpIgpyZXMyID0gcmUuZmluZGFsbChyeDIsIHMpCnByaW50KHJlczIpCgo=