Refractor: move 'to_env' to compat.py

src/dotenv/compat.py

@@ -1,12 +1,23 @@
 import sys
-from typing import Text
+from typing import Text  # noqa
 
-if sys.version_info >= (3, 0):
-    from io import StringIO  # noqa
-else:
+PY2 = sys.version_info[0] == 2  # type: bool
+
+if PY2:
     from StringIO import StringIO  # noqa
+else:
+    from io import StringIO  # noqa
 
-PY2 = sys.version_info[0] == 2  # type: bool
+
+def to_env(text):
+    # type: (Text) -> str
+    """
+    Encode a string the same way whether it comes from the environment or a `.env` file.
+    """
+    if PY2:
+        return text.encode(sys.getfilesystemencoding() or "utf-8")
+    else:
+        return text
 
 
 def to_text(string):

src/dotenv/main.py

@@ -14,7 +14,7 @@
 from collections import OrderedDict
 from contextlib import contextmanager
 
-from .compat import StringIO, PY2
+from .compat import StringIO, PY2, to_env
 from .parser import parse_stream
 
 if TYPE_CHECKING:  # pragma: no cover
@@ -31,17 +31,6 @@
 __posix_variable = re.compile(r'\$\{[^\}]*\}')  # type: Pattern[Text]
 
 
-def to_env(text):
-    # type: (Text) -> str
-    """
-    Encode a string the same way whether it comes from the environment or a `.env` file.
-    """
-    if PY2:
-        return text.encode(sys.getfilesystemencoding() or "utf-8")
-    else:
-        return text
-
-
 class DotEnv():
 
     def __init__(self, dotenv_path, verbose=False, encoding=None):