<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def com_google_fonts_check_metadata_match_fullname_postscript(font_metadata):
 """METADATA.pb font.full_name and font.post_script_name fields have equivalent values ? """

  import re
  regex = re.compile(r"\W")
  post_script_name = regex.sub("", font_metadata.post_script_name)
  fullname = regex.sub("", font_metadata.full_name)
  if fullname != post_script_name:
    yield FAIL, ("METADATA.pb font full_name=\"{}\""
                 " does not match post_script_name ="
                 " \"{}\"").format(font_metadata.full_name,
                                   font_metadata.post_script_name)
  else:
    yield PASS, ("METADATA.pb font fields \"full_name\" and"
                 " \"post_script_name\" have equivalent values.")