Moved FileString and get_file() into utility.py

1 files changed, 51 insertions, 0 deletions

diff --git a/libbe/utility.py b/libbe/utility.py
new file mode 100644
index 0000000..a67037d
--- /dev/null
+++ b/libbe/utility.py
@@ -0,0 +1,51 @@
+class FileString(object):
+    """Bare-bones pseudo-file class
+    
+    >>> f = FileString("me\\nyou")
+    >>> len(list(f))
+    2
+    >>> len(list(f))
+    0
+    >>> f = FileString()
+    >>> f.write("hello\\nthere")
+    >>> "".join(list(f))
+    'hello\\nthere'
+    """
+    def __init__(self, str=""):
+        object.__init__(self)
+        self.str = str
+        self._iter = None
+
+    def __iter__(self):
+        if self._iter is None:
+            self._iter = self._get_iter()
+        return self._iter
+
+    def _get_iter(self):
+        for line in self.str.splitlines(True):
+            yield line
+
+    def write(self, line):
+        self.str += line
+
+
+def get_file(f):
+    """
+    Return a file-like object from input.  This is a helper for functions that
+    can take either file or string parameters.
+
+    :param f: file or string
+    :return: a FileString if input is a string, otherwise return the imput 
+    object.
+
+    >>> isinstance(get_file(file("/dev/null")), file)
+    True
+    >>> isinstance(get_file("f"), FileString)
+    True
+    """
+    if isinstance(f, basestring):
+        return FileString(f)
+    else:
+        return f
+
+