X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=id_generator.py;h=dc2ac9cc810a4e1d588d60231371e873d9d31966;hb=1ee64f3522abbbc2df154c8f44be87929a16e17e;hp=cc287bb5819e0f31db1e504f0a136b1333f79dfe;hpb=497fb9e21f45ec08e1486abaee6dfa7b20b8a691;p=python_utils.git

diff --git a/id_generator.py b/id_generator.py
index cc287bb..dc2ac9c 100644
--- a/id_generator.py
+++ b/id_generator.py
@@ -1,19 +1,41 @@
 #!/usr/bin/env python3
 
+"""A helper class for generating thread safe monotonically increasing
+id numbers."""
+
 import itertools
 import logging
 
+# This module is commonly used by others in here and should avoid
+# taking any unnecessary dependencies back on them.
+
 logger = logging.getLogger(__name__)
 generators = {}
 
 
-def get(name: str) -> int:
+def get(name: str, *, start=0) -> int:
     """
-    def __init__(self):
-        self.my_unique_id = id_generator.get("student_id")
+    Returns a thread safe monotonically increasing id suitable for use
+    as a globally unique identifier.
+
+    >>> import id_generator
+    >>> id_generator.get('student_id')
+    0
+    >>> id_generator.get('student_id')
+    1
+    >>> id_generator.get('employee_id', start=10000)
+    10000
+    >>> id_generator.get('employee_id', start=10000)
+    10001
     """
     if name not in generators:
-        generators[name] = itertools.count()
+        generators[name] = itertools.count(start, 1)
     x = next(generators[name])
-    logger.debug(f"Generated next id {x}")
+    logger.debug("Generated next id %d", x)
     return x
+
+
+if __name__ == '__main__':
+    import doctest
+
+    doctest.testmod()