diff env/lib/python3.9/site-packages/humanfriendly/decorators.py @ 0:4f3585e2f14b draft default tip

"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.9/site-packages/humanfriendly/decorators.py	Mon Mar 22 18:12:50 2021 +0000
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+# Human friendly input/output in Python.
+#
+# Author: Peter Odding <[e-mail]>
+# Last Change: March 2, 2020
+# URL: https://humanfriendly.readthedocs.io
+
+"""Simple function decorators to make Python programming easier."""
+
+# Standard library modules.
+import functools
+
+# Public identifiers that require documentation.
+__all__ = ('RESULTS_ATTRIBUTE', 'cached')
+
+RESULTS_ATTRIBUTE = 'cached_results'
+"""The name of the property used to cache the return values of functions (a string)."""
+
+
+def cached(function):
+    """
+    Rudimentary caching decorator for functions.
+
+    :param function: The function whose return value should be cached.
+    :returns: The decorated function.
+
+    The given function will only be called once, the first time the wrapper
+    function is called. The return value is cached by the wrapper function as
+    an attribute of the given function and returned on each subsequent call.
+
+    .. note:: Currently no function arguments are supported because only a
+              single return value can be cached. Accepting any function
+              arguments at all would imply that the cache is parametrized on
+              function arguments, which is not currently the case.
+    """
+    @functools.wraps(function)
+    def wrapper():
+        try:
+            return getattr(wrapper, RESULTS_ATTRIBUTE)
+        except AttributeError:
+            result = function()
+            setattr(wrapper, RESULTS_ATTRIBUTE, result)
+            return result
+    return wrapper