Small cleanups to dviread.

anntzer · anntzer · commit 32411ca8a63e · 2020-03-22T19:31:41.000+01:00
Don't use variables whose name shadow builtins (`bytes`, `str` -- the
latter is actually a bytes instance).  Also use a slightly more
idiomatic way to iterate over the bytestring.
diff --git a/lib/matplotlib/dviread.py b/lib/matplotlib/dviread.py
@@ -73,10 +73,10 @@ def _arg_raw(dvi, delta):
     return delta
 
 
-def _arg(bytes, signed, dvi, _):
-    """Read *bytes* bytes, returning the bytes interpreted as a
+def _arg(nbytes, signed, dvi, _):
+    """Read *nbytes* bytes, returning the bytes interpreted as a
     signed integer if *signed* is true, unsigned otherwise."""
-    return dvi._arg(bytes, signed)
+    return dvi._arg(nbytes, signed)
 
 
 def _arg_slen(dvi, delta):
@@ -304,12 +304,12 @@ def _arg(self, nbytes, signed=False):
         Read and return an integer argument *nbytes* long.
         Signedness is determined by the *signed* keyword.
         """
-        str = self.file.read(nbytes)
-        value = str[0]
+        buf = self.file.read(nbytes)
+        value = buf[0]
         if signed and value >= 0x80:
             value = value - 0x100
-        for i in range(1, nbytes):
-            value = 0x100*value + str[i]
+        for b in buf[1:]:
+            value = 0x100*value + b
         return value
 
     @_dispatch(min=0, max=127, state=_dvistate.inpage)
