General PyGreSQL programming information¶
If you use only the standard features of the DB-API 2.0 interface, it will be easier to switch from PostgreSQL to another database for which a DB-API 2.0 compliant interface exists.
The “classic” interface may be easier to use for beginners, and it provides some higher-level and PostgreSQL specific convenience methods.
DB-API 2.0 (Python Database API Specification v2.0) is a specification for connecting to databases (not only PostgreSQL) from Python that has been developed by the Python DB-SIG in 1999. The authoritative programming information for the DB-API is PEP 0249.
Both Python modules utilize the same low-level C extension, which serves as a wrapper for the “libpq” library, the C API to PostgreSQL.
This means you must have the libpq library installed as a shared library on your client computer, in a version that is supported by PyGreSQL. Depending on the client platform, you may have to set environment variables like PATH or LD_LIBRARY_PATH so that PyGreSQL can find the library.
Note that PyGreSQL is not thread-safe on the connection level. Therefore we recommend using DBUtils for multi-threaded environments, which supports both PyGreSQL interfaces.
Another option is using PyGreSQL indirectly as a database driver for the high-level SQLAlchemy SQL toolkit and ORM, which supports PyGreSQL starting with SQLAlchemy 1.1 and which provides a way to use PyGreSQL in a multi-threaded environment using the concept of “thread local storage”. Database URLs for PyGreSQL take this form: