Connascence of Name

Connascence of name is when multiple components must agree on the name of an entity. Method names are an example of this form of connascence: if the name of a method changes, callers of that method must be changed to use the new name.

Almost any code example involves connascence of name. Consider the following class declaration taken from the Python standard library (method implementation has been omitted for clarity):

class Request:

    def __init__(self, url, data=None, headers={},
                 origin_req_host=None, unverifiable=False,

    def set_proxy(self, host, type):

Changing the name of any part of this code will cause code that uses this class to break, including:

  • Changing the class name from Request.
  • Changing any of the method names (such as set_proxy).
  • Changing the name of any of the parameters to either __init__ or set_proxy.

Connascence of name is unavoidable, since we refer to entities using labels. If we change the name of an entity when we declare it, we must also change all code that refers to that entity. For this reason, connascence of name is the weakest connascence. However, it also illustrates how important it is to name entities in code well.