→ context-managerscontext-managers/

context-managers/context-managers.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python2.7
+
+# Examples from:
+# https://stackoverflow.com/questions/3012488/what-is-the-python-with-statement-designed-for
+
+from contextlib import contextmanager
+from tempfile import mkdtemp
+
+import os
+import shutil
+
+
+@contextmanager
+def working_directory(path):
+    current_dir = os.getcwd()
+    os.chdir(path)
+    try:
+        yield
+    finally:
+        os.chdir(current_dir)
+
+
+@contextmanager
+def just_a_test():
+    try:
+        print "just trying..."
+        yield
+    finally:
+        print "finally!"
+
+
+@contextmanager
+def temporary_dir(*args, **kwds):
+    name = mkdtemp(*args, **kwds)
+    try:
+        yield name
+    finally:
+        shutil.rmtree(name)
+
+
+with working_directory("/tmp"), just_a_test():
+    # do something within data/stuff
+    print os.getcwd()
+
+# here I am back again in the original working directory
+print os.getcwd()
+
+
+with temporary_dir() as tmpdir:
+    print tmpdir
+    tmpfile = tmpdir + "/foo"
+    with open(tmpfile, "w") as f:
+        f.write("foo")
+
+# tmpdir is now gone