Python Morsels: Python Built-in Functions To Know

Table of contents

1. Which built-ins should you know about?
2. The 10 commonly known built-in functions
3. The 10 commonly overlooked built-ins
4. The 5 built-ins for debugging
5. Learn these later
6. Maybe learn these eventually
7. You likely don't need these
8. There's always more to learn

Which built-ins should you know about?

I estimate most Python developers will only ever need about 30 built-in functions, but which 30 depends on what you're actually doing with Python.

We're going to take a look at all 71 of Python's built-in functions, in a birds eye view sort of way.

I'll attempt to categorize these built-ins into five categories:

1. Commonly known built-ins: most newer Pythonistas get exposure to these built-ins pretty quickly out of necessity
2. Overlooked by new Pythonistas: these functions are useful to know about, but they're easy to overlook when you're newer to Python
3. Learn these later: these built-ins are generally useful to know about, but you'll find them when/if you need them
4. Maybe learn these eventually: these can come in handy, but only in specific circumstances
5. You likely don't need these: you're unlikely to need these unless you're doing something fairly specialized

The built-in functions in categories 1 and 2 are the essential built-ins that nearly all Python programmers should eventually learn about. The built-ins in categories 3 and 4 are the specialized built-ins, which are often very useful but your need for them will vary based on your use for Python. And category 5 are arcane built-ins, which might be very handy when you need them but which many Python programmers are likely to never need.

Note for pedantic Pythonistas: I will be referring to all of these built-ins as functions, even though 27 of them aren't actually functions.

The commonly known built-in functions (which you likely already know about):

1. print
2. len
3. str
4. int
5. float
6. list
7. tuple
8. dict
9. set
10. range

The built-in functions which are often overlooked by newer Python programmers:

1. sum
2. enumerate
3. zip
4. bool
5. reversed
6. sorted
7. min
8. max
9. any
10. all

There are also 5 commonly overlooked built-ins which I recommend knowing about solely because they make debugging easier:

1. dir
2. vars
3. breakpoint
4. type
5. help

In addition to the 25 built-in functions above, we'll also briefly see the other 46 built-ins in the learn it latermaybe learn it eventually and you likely don't need these sections.

The 10 commonly known built-in functions

If you've been writing Python …