Flush stdin before attempting to read from stderr.

Fixes #17

Author: nvcleemp

sage/conjecturing.py

@@ -460,15 +460,15 @@ def get_value(invariant, o):
             except:
                 stdin.write('NaN\n')
 
+    stdin.flush()
+
     if verbose:
         print("Finished computing and writing invariant values to expressions")
 
     if debug:
         for l in sp.stderr:
             print('> ' + l.rstrip())
 
-    stdin.flush()
-
     # process the output
     out = sp.stdout
 
@@ -761,15 +761,15 @@ def get_value(prop, o):
             except:
                 stdin.write('-1\n')
 
+    stdin.flush()
+
     if verbose:
         print("Finished computing and writing property values to expressions")
 
     if debug:
         for l in sp.stderr:
             print('> ' + l.rstrip())
 
-    stdin.flush()
-
     # process the output
     out = sp.stdout