regex - Substituting leading '+1' in Python with re module -

I'm sure it's definitely a simple and stupid question, but I'm not sure how the leading " By using the sub () module of + 1 " again module I'm trying this

  import re re.ub ("/ + 1", "", "+ 1585123456") re.sub (r "^ / + 1", " , "+ 1585123456")   
 but they all return the same original string. Can anyone help me make a clear mistake I am? Thank you.   
 
 
  << code> to avoid using  + ,  /   
  re.sub (r "\ + 1", "", "+ 1585123456")