Expert Python Programming - Third Edition

Changes in the standard library

Breaking changes in the standard library are the second easiest to catch after syntax changes. Each subsequent version of Python adds, deprecates, improves, or completely removes standard library modules. Such a process was also common in the older branches of Python (1.x and 2.x), so it does not come as a shock in Python 3. In most cases, depending on the module that was removed or reorganized (such as urlparse being moved to urllib.parse), it will raise exceptions on the import time just after it is interpreted. This makes such issues so easy to catch. In order to be sure that all such issues are covered, full test code coverage is essential. In some cases (for example, when using lazily loaded modules), ...