python学习

venv/Lib/site-packages/flask_sqlalchemy/_compat.py

@@ -0,0 +1,44 @@
+import sys
+
+PY2 = sys.version_info[0] == 2
+
+
+if PY2:
+    def iteritems(d):
+        return d.iteritems()
+
+    def itervalues(d):
+        return d.itervalues()
+
+    xrange = xrange
+
+    string_types = (unicode, bytes)
+
+    def to_str(x, charset='utf8', errors='strict'):
+        if x is None or isinstance(x, str):
+            return x
+
+        if isinstance(x, unicode):
+            return x.encode(charset, errors)
+
+        return str(x)
+
+else:
+    def iteritems(d):
+        return iter(d.items())
+
+    def itervalues(d):
+        return iter(d.values())
+
+    xrange = range
+
+    string_types = (str,)
+
+    def to_str(x, charset='utf8', errors='strict'):
+        if x is None or isinstance(x, str):
+            return x
+
+        if isinstance(x, bytes):
+            return x.decode(charset, errors)
+
+        return str(x)