Producing readable and correct programs while at the same time taking advantage of multi-core architectures is a challenge. PyCSP is an implementation of Communicating Sequential Processes algebra (CSP) for the Python programming language, taking advantage of CSP’s formal and verifiable approach to controlling concurrency and the readability of Python source code. We describe PyCSP, demonstrate it through examples and demonstrate how PyCSP compares to Pthreads using a benchmark.