import re
zz = 'options={}, params={vector_name=get_x, default_like_count=2, setting_id=1200, system=0 back options={}, params={vector_name=get_x, default_like_count=2, setting_id=1200, system=0 back'
m = re.search(r'vector_name=(\w+)', zz)
if m:
print(m.group(1))
aW1wb3J0IHJlCnp6ID0gJ29wdGlvbnM9e30sIHBhcmFtcz17dmVjdG9yX25hbWU9Z2V0X3gsIGRlZmF1bHRfbGlrZV9jb3VudD0yLCBzZXR0aW5nX2lkPTEyMDAsIHN5c3RlbT0wIGJhY2sgb3B0aW9ucz17fSwgcGFyYW1zPXt2ZWN0b3JfbmFtZT1nZXRfeCwgZGVmYXVsdF9saWtlX2NvdW50PTIsIHNldHRpbmdfaWQ9MTIwMCwgc3lzdGVtPTAgYmFjaycKbSA9IHJlLnNlYXJjaChyJ3ZlY3Rvcl9uYW1lPShcdyspJywgenopCmlmIG06CglwcmludChtLmdyb3VwKDEpKQ==