vppapigen map: raise ValueError when fieldname is python keyword

When working on the lb api, one of the field names was chosen as 'as'
(application server). Since 'as' is a python keyword, the field was
renamed to _1 in vpp_papi.

This changeset instead fails early with a descriptive message,
hopefully saving others time troubleshooting the issue.

    ValueError: Fieldname 'as' is a python keyword and
    is not accessible via the python API.

Type: feature
Change-Id: Ib048d97de0e392645540092e356cf8989848c947
Signed-off-by: Paul Vinciguerra <pvinci@vinciconsulting.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/tools/vppapigen/vppapigen.py b/src/tools/vppapigen/vppapigen.py
index 8ae991c9c95..52ffb6a18f1 100755
--- a/src/tools/vppapigen/vppapigen.py
+++ b/src/tools/vppapigen/vppapigen.py
@@ -5,6 +5,7 @@ import ply.lex as lex
 import ply.yacc as yacc
 import sys
 import argparse
+import keyword
 import logging
 import binascii
 import os
@@ -293,6 +294,9 @@ class Field():
     def __init__(self, fieldtype, name, limit=None):
         self.type = 'Field'
         self.fieldtype = fieldtype
+        if name in keyword.kwlist:
+            raise ValueError("Fieldname {!r} is a python keyword and is not "
+                             "accessible via the python API. ".format(name))
         self.fieldname = name
         self.limit = limit