Add Basic Authentication example.

examples/basic_auth.py

+import tweepy
+
+# === Basic Authentication ===
+#
+# *Note: Basic Authentication is deprecated and no longer supported on Twitter.
+#      It is still provided for use in services like Status.net which still suppports it.*
+#
+# This mode of authentication requires the user provide their username and plain text password.
+# These credentials will then be provided for each request to the API for authentication.
+
+# You would normally fetch this in your application
+# by asking the user or loading from some dark place.
+username = ""
+password = ""
+
+# Create an authentication handler passing it the username and password.
+# We will use this object later on when creating our API object.
+auth = tweepy.auth.BasicAuthHandler(username, password)
+
+# Create the API object providing it the authentication handler to use.
+# Each request will then be authenticated using this handler.
+api = tweepy.API(auth)
+
+api.update_status('Updating using basic authentication via Tweepy!')
+