pyln.proto.message: python-fluency feedback from @darosior

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Author: rustyrussell

contrib/pyln-proto/pyln/proto/message/array_types.py

@@ -34,19 +34,11 @@ def val_to_str(self, v, otherfields):
         if self.elemtype.name == 'byte':
             return bytes(v).hex()
 
-        s = ''
-        sep = ''
-        for i in v:
-            s += sep + self.elemtype.val_to_str(i, otherfields)
-            sep = ','
-
+        s = ','.join(self.elemtype.val_to_str(i, otherfields) for i in v)
         return '[' + s + ']'
 
     def val_to_bin(self, v, otherfields):
-        b = bytes()
-        for i in v:
-            b += self.elemtype.val_to_bin(i, otherfields)
-        return b
+        return b''.join(self.elemtype.val_to_bin(i, otherfields) for i in v)
 
     def arr_from_bin(self, bytestream, otherfields, arraysize):
         """arraysize None means take rest of bytestream exactly"""

contrib/pyln-proto/pyln/proto/message/message.py

@@ -63,7 +63,7 @@ def get_tlvtype(self, name):
 
     def get_type(self, name):
         t = self.get_subtype(name)
-        if not t:
+        if t is None:
             t = self.get_tlvtype(name)
         return t
 
@@ -178,7 +178,7 @@ def _field_from_csv(self, namespace, parts, ellipsisok=False, option=None):
 
         """
         basetype = namespace.get_type(parts[1])
-        if not basetype:
+        if basetype is None:
             raise ValueError('Unknown type {}'.format(parts[1]))
 
         # Fixed number, or another field.
@@ -345,7 +345,7 @@ def field_from_csv(namespace, parts):
             raise ValueError("msgdata expected 4 CSV parts, not {}"
                              .format(parts))
         messagetype = namespace.get_msgtype(parts[0])
-        if not messagetype:
+        if messagetype is None:
             raise ValueError("unknown subtype {}".format(parts[0]))
 
         field = messagetype._field_from_csv(namespace, parts[1:4],
@@ -383,7 +383,7 @@ def type_from_csv(namespace, parts):
             raise ValueError("tlvtype expected 4 CSV parts, not {}"
                              .format(parts))
         tlvstream = namespace.get_tlvtype(parts[0])
-        if not tlvstream:
+        if tlvstream is None:
             tlvstream = TlvStreamType(parts[0])
             namespace.add_tlvtype(tlvstream)
 
@@ -400,7 +400,7 @@ def field_from_csv(namespace, parts):
                              .format(parts))
 
         tlvstream = namespace.get_tlvtype(parts[0])
-        if not tlvstream:
+        if tlvstream is None:
             raise ValueError("unknown tlvtype {}".format(parts[0]))
 
         field = tlvstream.find_field(parts[1])
@@ -560,7 +560,7 @@ def from_bin(namespace, binmsg):
         off = 2
 
         mtype = namespace.get_msgtype_by_number(typenum)
-        if not mtype:
+        if mtype is None:
             raise ValueError('Unknown message type number {}'.format(typenum))
 
         fields = {}
@@ -578,7 +578,7 @@ def from_str(namespace, s, incomplete_ok=False):
         parts = s.split()
 
         mtype = namespace.get_msgtype(parts[0])
-        if not mtype:
+        if mtype is None:
             raise ValueError('Unknown message type name {}'.format(parts[0]))
 
         args = {}