Initial commit of item_03

Author: craigem

item_03.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+
+'''Item 3 from Effective Python'''
+
+import logging
+from pprint import pprint
+from sys import stdout as STDOUT
+
+
+# Example 1
+def to_str(bytes_or_str):
+    '''In Python 3, you’ll need one method that takes a str or bytes and
+    always returns a str .'''
+    if isinstance(bytes_or_str, bytes):
+        value = bytes_or_str.decode('utf-8')
+    else:
+        value = bytes_or_str
+    return value  # Instance of str
+
+print(repr(to_str(b'foo')))
+print(repr(to_str('foo')))
+
+
+# Example 2
+def to_bytes(bytes_or_str):
+    '''You’ll need another method that takes a str or bytes and always
+    returns a bytes .'''
+    if isinstance(bytes_or_str, str):
+        value = bytes_or_str.encode('utf-8')
+    else:
+        value = bytes_or_str
+    return value  # Instance of bytes
+
+print(repr(to_bytes(b'foo')))
+print(repr(to_bytes('foo')))
+
+
+# Example 5
+try:
+    import os
+    with open('random.bin', 'wb') as f:
+        f.write(os.urandom(10))
+except:
+    logging.exception('Expected')
+else:
+    exit()
+
+
+# Example 6
+with open('random1.bin', 'wb') as f:
+    f.write(os.urandom(10))