import re
def split_merged_json(s):
prev = 0
for m in re.finditer(r'(?<=\})(?=\{)', s):
yield s[prev: m.end()]
prev = m.end()
yield s[prev:]
s = '{"text": "Welcome!"}{"ID": 0}{"text": "Hello, world"}'
print list(split_merged_json(s))
aW1wb3J0IHJlCgoKZGVmIHNwbGl0X21lcmdlZF9qc29uKHMpOgogICAgcHJldiA9IDAKICAgIGZvciBtIGluIHJlLmZpbmRpdGVyKHInKD88PVx9KSg/PVx7KScsIHMpOgogICAgICAgIHlpZWxkIHNbcHJldjogbS5lbmQoKV0KICAgICAgICBwcmV2ID0gbS5lbmQoKQogICAgICAgIAogICAgeWllbGQgc1twcmV2Ol0KCnMgPSAneyJ0ZXh0IjogIldlbGNvbWUhIn17IklEIjogMH17InRleHQiOiAiSGVsbG8sIHdvcmxkIn0nCgpwcmludCBsaXN0KHNwbGl0X21lcmdlZF9qc29uKHMpKQ==