Merge pull request #221 from Li-Xiang-Ideal/patch-1

Update __init__.py

cairocffi/__init__.py

@@ -9,7 +9,9 @@
 
 """
 
+import os
 import sys
+from contextlib import suppress
 from ctypes.util import find_library
 
 from . import constants
@@ -21,6 +23,17 @@
 version_info = (1, 17, 2)
 
 
+# Python 3.8 no longer searches for DLLs in PATH, so we can add everything in
+# CAIROCFFI_DLL_DIRECTORIES manually. Note that unlike PATH, add_dll_directory
+# has no defined order, so if there are two cairo DLLs in PATH we might get a
+# random one.
+dll_directories = os.getenv('CAIROCFFI_DLL_DIRECTORIES')
+if dll_directories and hasattr(os, 'add_dll_directory'):
+    for path in dll_directories.split(';'):
+        with suppress((OSError, FileNotFoundError)):
+            os.add_dll_directory(path)
+
+
 def dlopen(ffi, library_names, filenames):
     """Try various names for the same library, for different platforms."""
     exceptions = []

docs/overview.rst

@@ -60,9 +60,13 @@ If it fails to find it, you will see an exception like this::
 
 Make sure cairo is correctly installed and available through your system’s
 usual mechanisms.
+
 On Linux, the ``LD_LIBRARY_PATH`` environment variable can be used to indicate
 where to find shared libraries.
 
+On Windows, you can put the folder where Cairo and other DLLs are installed in
+the ``CAIROCFFI_DLL_DIRECTORIES`` environment variable.
+
 .. _Pycairo: http://cairographics.org/pycairo/