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THIRTYFIVE

USING THE ZOPE COMPONENT ARCHITECTURE IN PYRAMID

Under the hood, Pyramid uses a Zope Component Architecture component registry as its application registry. The Zope Component Architecture is referred to colloquially as the “ZCA.”

The zope.component API used to access data in a traditional Zope application can be opaque. For example, here is a typical “unnamed utility” lookup using the zope.component.getUtility() global API as it might appear in a traditional Zope application:

After this code runs, settings will be a Python dictionary. But it’s unlikely that any “civilian” will be able to figure this out just by reading the code casually. When the zope.component.getUtility API is used by a developer, the conceptual load on a casual reader of code is high.

While the ZCA is an excellent tool with which to build a framework such as Pyramid, it is not always the best tool with which to build an application due to the opacity of the zope.component APIs. Accordingly, Pyramid tends to hide the presence of the ZCA from application developers. You needn’t understand the ZCA to create a Pyramid application; its use is effectively only a framework implementation detail.

However, developers who are already used to writing Zope applications often still wish to use the ZCA while building a Pyramid application; pyramid makes this possible.

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