seanh · November 12, 2009 11:19 · Nov 12, 2009
diff --git a/gistfile1.py b/gistfile1.py
@@ -0,0 +1,26 @@
+# Write mode creates a new file or overwrites the existing content of the file. 
+# Write mode will _always_ destroy the existing contents of a file.
+try:
+    # This will create a new file or **overwrite an existing file**.
+    f = open("file.txt", "w")
+    try:
+        f.write('blah') # Write a string to a file
+        f.writelines(lines) # Write a sequence of strings to a file
+    finally:
+        f.close()
+except IOError:
+    pass
+
+# Append mode adds to the existing content, e.g. for keeping a log file. Append
+# mode will _never_ harm the existing contents of a file.
+try:
+    # This tries to open an existing file but creates a new file if necessary.
+    logfile = open("log.txt", "a")
+    try:
+        logfile.write('log log log')
+    finally:
+        logfile.close()
+except IOError:
+    pass
+
+# There are also r (read) and r+ (read and write) modes.