Summary

We've covered string manipulation, file IO, and object serialization. We discussed how to combine hard-coded strings and program variables into outputtable strings using the powerful string formatting system, and learned the difference between binary and textual data. All told, we've seen:

• How to use the various str methods
• String formatting
• bytes versus str
• Mutable bytearrays
• Files in binary and textual formatters
• Context managers and the with statement
• Serializing data with pickle and json

In the next chapter, we'll cover one of the most important topics in Python programming: how to test our code to ensure it's doing what we think it is doing.