changeset 73:ca5a822c550a

Fix for Python 3 Add getbin function to read large non-arrat data blocks (eg screen capture)
author Daniel O'Connor <doconnor@gsoft.com.au>
date Wed, 25 Sep 2024 20:57:26 +0930
parents da3558dec4e3
children b6ebe05f250f
files scpi.py
diffstat 1 files changed, 16 insertions(+), 11 deletions(-) [+]
line wrap: on
line diff
--- a/scpi.py	Wed Sep 25 20:56:39 2024 +0930
+++ b/scpi.py	Wed Sep 25 20:57:26 2024 +0930
@@ -28,8 +28,8 @@
 import numpy
 import re
 
-headerre = re.compile('^(:[A-Z:]+ ).*') 
-insturlre = re.compile('([a-zA-Z0-9]+)://(([^:]+)?(:([^/]+)@))?([^:]+)(:(.+))?')
+headerre = re.compile(b'^(:[A-Z:]+ ).*')
+insturlre = re.compile(b'([a-zA-Z0-9]+)://(([^:]+)?(:([^/]+)@))?([^:]+)(:(.+))?')
 
 def query(d, q, timeout = None):
     d.write(q)
@@ -49,29 +49,34 @@
     data = clean(data)
     return dtype(data)
 
-def bindecode(data, dtype = numpy.float32):
-    '''Decode binary data, returns numpy array'''
-
+def getbin(data):
+    '''Fetch binary blob, strips ASCII length header and checks'''
     data = clean(data)
 
-    if data[0] != '#':
+    if data[0] != ord('#'):
         raise ValueError('data length header incorrect')
-    dlenlen = int(data[1])
+    dlenlen = int(chr(data[1]))
     if dlenlen == 0:
         return numpy.array([])
-    
+
     dlen = int(data[2:dlenlen + 2])
     if dlen == 0:
-        return numpy.array([])
+        return b''
 
     wanted = dlen + 2 + dlenlen
     # Chop off the trailing \n if necessary
     if len(data) == wanted + 1 and data[-1] == '\n':
         data = data[0:-1]
-        
+
     if len(data) != wanted:
         raise ValueError('length mismatch, header says %d, actually got %d bytes' % (wanted, len(data)))
-    return numpy.frombuffer(data[2 + dlenlen:], dtype = dtype)
+
+    return data[2 + dlenlen:]
+
+def bindecode(data, dtype = numpy.float32):
+    '''Decode binary data, returns numpy array'''
+
+    return numpy.frombuffer(getbin(data), dtype = dtype)
 
 def ascdecode(data, dtype = numpy.float32, sep = None):
     '''Decode ASCII data, returns numpy array'''