Merge pull request #6 from scardine/master

Suggestions for #4 and #2, general code janitoring.

validate_email.py

@@ -19,14 +19,18 @@
 
 import re
 import smtplib
+import logging
 import socket
 
 try:
     import DNS
     ServerError = DNS.ServerError
-except:
+except ImportError:
     DNS = None
-    class ServerError(Exception): pass
+
+    class ServerError(Exception):
+        pass
+
 # All we are really doing is comparing the input string to one
 # gigantic regular expression.  But building that regexp, and
 # ensuring its correctness, is made much easier by assembling it
@@ -45,44 +49,44 @@ CRLF = r'(?:\r\n)'                                   # see 2.2.3. Long Header Fi
 NO_WS_CTL = r'\x01-\x08\x0b\x0c\x0f-\x1f\x7f'        # see 3.2.1. Primitive Tokens
 QUOTED_PAIR = r'(?:\\.)'                             # see 3.2.2. Quoted characters
 FWS = r'(?:(?:' + WSP + r'*' + CRLF + r')?' + \
-            WSP + r'+)'                                    # see 3.2.3. Folding white space and comments
+      WSP + r'+)'                                    # see 3.2.3. Folding white space and comments
 CTEXT = r'[' + NO_WS_CTL + \
-                r'\x21-\x27\x2a-\x5b\x5d-\x7e]'              # see 3.2.3
+        r'\x21-\x27\x2a-\x5b\x5d-\x7e]'              # see 3.2.3
 CCONTENT = r'(?:' + CTEXT + r'|' + \
-                     QUOTED_PAIR + r')'                        # see 3.2.3 (NB: The RFC includes COMMENT here
-                                                                                                         # as well, but that would be circular.)
+           QUOTED_PAIR + r')'                        # see 3.2.3 (NB: The RFC includes COMMENT here
+# as well, but that would be circular.)
 COMMENT = r'\((?:' + FWS + r'?' + CCONTENT + \
-                    r')*' + FWS + r'?\)'                       # see 3.2.3
+          r')*' + FWS + r'?\)'                       # see 3.2.3
 CFWS = r'(?:' + FWS + r'?' + COMMENT + ')*(?:' + \
-             FWS + '?' + COMMENT + '|' + FWS + ')'         # see 3.2.3
+       FWS + '?' + COMMENT + '|' + FWS + ')'         # see 3.2.3
 ATEXT = r'[\w!#$%&\'\*\+\-/=\?\^`\{\|\}~]'           # see 3.2.4. Atom
 ATOM = CFWS + r'?' + ATEXT + r'+' + CFWS + r'?'      # see 3.2.4
 DOT_ATOM_TEXT = ATEXT + r'+(?:\.' + ATEXT + r'+)*'   # see 3.2.4
 DOT_ATOM = CFWS + r'?' + DOT_ATOM_TEXT + CFWS + r'?' # see 3.2.4
 QTEXT = r'[' + NO_WS_CTL + \
-                r'\x21\x23-\x5b\x5d-\x7e]'                   # see 3.2.5. Quoted strings
+        r'\x21\x23-\x5b\x5d-\x7e]'                   # see 3.2.5. Quoted strings
 QCONTENT = r'(?:' + QTEXT + r'|' + \
-                     QUOTED_PAIR + r')'                        # see 3.2.5
+           QUOTED_PAIR + r')'                        # see 3.2.5
 QUOTED_STRING = CFWS + r'?' + r'"(?:' + FWS + \
-                                r'?' + QCONTENT + r')*' + FWS + \
-                                r'?' + r'"' + CFWS + r'?'
+                r'?' + QCONTENT + r')*' + FWS + \
+                r'?' + r'"' + CFWS + r'?'
 LOCAL_PART = r'(?:' + DOT_ATOM + r'|' + \
-                         QUOTED_STRING + r')'                    # see 3.4.1. Addr-spec specification
+             QUOTED_STRING + r')'                    # see 3.4.1. Addr-spec specification
 DTEXT = r'[' + NO_WS_CTL + r'\x21-\x5a\x5e-\x7e]'    # see 3.4.1
 DCONTENT = r'(?:' + DTEXT + r'|' + \
-                     QUOTED_PAIR + r')'                        # see 3.4.1
+           QUOTED_PAIR + r')'                        # see 3.4.1
 DOMAIN_LITERAL = CFWS + r'?' + r'\[' + \
-                                 r'(?:' + FWS + r'?' + DCONTENT + \
-                                 r')*' + FWS + r'?\]' + CFWS + r'?'  # see 3.4.1
+                 r'(?:' + FWS + r'?' + DCONTENT + \
+                 r')*' + FWS + r'?\]' + CFWS + r'?'  # see 3.4.1
 DOMAIN = r'(?:' + DOT_ATOM + r'|' + \
-                 DOMAIN_LITERAL + r')'                       # see 3.4.1
+         DOMAIN_LITERAL + r')'                       # see 3.4.1
 ADDR_SPEC = LOCAL_PART + r'@' + DOMAIN               # see 3.4.1
 
 # A valid address will match exactly the 3.4.1 addr-spec.
 VALID_ADDRESS_REGEXP = '^' + ADDR_SPEC + '$'
 
-def validate_email(email, check_mx=False,verify=False):
 
+def validate_email(email, check_mx=False, verify=False, debug=False):
     """Indicate whether the given string is a valid email address
     according to the 'addr-spec' portion of RFC 2822 (see section
     3.4.1).  Parts of the spec that are marked obsolete are *not*
@@ -90,13 +94,21 @@ def validate_email(email, check_mx=False,verify=False):
     depend on circular definitions in the spec may not pass, but in
     general this should correctly identify any email address likely
     to be in use as of 2011."""
+    if debug:
+        logger = logging.getLogger('validate_email')
+        logger.setLevel(logging.DEBUG)
+    else:
+        logger = None
+
     try:
         assert re.match(VALID_ADDRESS_REGEXP, email) is not None
         check_mx |= verify
         if check_mx:
-            if not DNS: raise Exception('For check the mx records or check if the email exists you must have installed pyDNS python package')
+            if not DNS:
+                raise Exception('For check the mx records or check if the email exists you must '
+                                'have installed pyDNS python package')
             DNS.DiscoverNameServers()
-            hostname = email[email.find('@')+1:]
+            hostname = email[email.find('@') + 1:]
             mx_hosts = DNS.mxlookup(hostname)
             for mx in mx_hosts:
                 try:
@@ -108,22 +120,62 @@ def validate_email(email, check_mx=False,verify=False):
                     status, _ = smtp.helo()
                     if status != 250:
                         smtp.quit()
+                        if debug:
+                            logger.debug(u'%s answer: %s - %s', mx[1], status, _)
                         continue
                     smtp.mail('')
                     status, _ = smtp.rcpt(email)
-                    if status != 250:
+                    if status == 250:
                         smtp.quit()
-                        return False
+                        return True
+                    if debug:
+                        logger.debug(u'%s answer: %s - %s', mx[1], status, _)
                     smtp.quit()
-                    break
-                except smtplib.SMTPServerDisconnected: #Server not permits verify user
-                    break
+                except smtplib.SMTPServerDisconnected:  # Server not permits verify user
+                    if debug:
+                        logger.debug(u'%s disconected.', mx[1])
                 except smtplib.SMTPConnectError:
-                    continue
-    except (AssertionError, ServerError): 
+                    if debug:
+                        logger.debug(u'Unable to connect to %s.', mx[1])
+            return None
+    except AssertionError:
         return False
+    except (ServerError, socket.error) as e:
+        if debug:
+            logger.debug('ServerError or socket.error exception raised (%s).', e)
+        return None
     return True
 
+if __name__ == "__main__":
+    import time
+    while True:
+        email = raw_input('Enter email for validation: ')
+
+        mx = raw_input('Validate MX record? [yN] ')
+        if mx.strip().lower() == 'y':
+            mx = True
+        else:
+            mx = False
+
+        validate = raw_input('Try to contact server for address validation? [yN] ')
+        if validate.strip().lower() == 'y':
+            validate = True
+        else:
+            validate = False
+
+        logging.basicConfig()
+
+        result = validate_email(email, mx, validate, debug=True)
+        if result:
+            print "Valid!"
+        elif result is None:
+            print "I'm not sure."
+        else:
+            print "Invalid!"
+
+        time.sleep(1)
+
+
 # import sys
 
 # sys.modules[__name__],sys.modules['validate_email_module'] = validate_email,sys.modules[__name__]