Overload of the subprocess module (check_call and check_output) to be able to...

Overload of the subprocess module (check_call and check_output) to be able to specify the retcode expected

MDmisc/mysubprocess.py

+#!/usr/bin/python
+# -*- coding: UTF-8 -*-
+
+from subprocess import Popen, PIPE, call
+
+class CalledProcessError( Exception ):
+    def __init__( self, returncode, cmd, output = None, expectedReturnCode = 0 ):
+        self.returncode = returncode
+        self.expectedReturnCode = expectedReturnCode
+        self.cmd = cmd
+        self.output = output
+    
+    def __str__( self ):
+        return "Command '%s' returned %d, expected %d" % ( self.cmd, self.returncode, self.expectedReturnCode )
+
+def check_call(*popenargs, **kwargs):
+    retcode = call(*popenargs, **kwargs)
+    if retcode:
+        cmd = kwargs.get("args")
+        if cmd is None:
+            cmd = popenargs[0]
+        raise CalledProcessError(retcode, cmd)
+    return 0
+
+def check_output( *popenargs, **kwargs ):
+    if 'stdout' in kwargs:
+        raise ValueError('stdout argument not allowed, it will be overridden.')
+    
+    expectedReturnCode = kwargs.pop( "expectedReturnCode", 0 )
+    
+    process = Popen( stdout = PIPE, *popenargs, **kwargs )
+    output, unused_err = process.communicate()
+    retcode = process.poll()
+    
+    if retcode != expectedReturnCode:
+        cmd = kwargs.get( "args" )
+        
+        if cmd is None:
+            cmd = popenargs[ 0 ]
+        
+        raise CalledProcessError( retcode, cmd, output = output, expectedReturnCode = expectedReturnCode )
+    
+    return output