Improve Your Python With:

🐍 Python Tricks 💌

Get a short & sweet Python Trick delivered to your inbox every couple of days:

🐍 Python Tricks 💌

Get a short & sweet Python Trick delivered to your inbox every couple of days. No spam ever. Unsubscribe any time. Curated by the Real Python team.

Python Tricks Dictionary Merge
Python Tricks

Q: What’s a Python Trick?

A short Python code snippet meant as a teaching tool. A Python Trick either teaches an aspect of Python with a simple illustration, or serves as a motivating example to dig deeper and develop an intuitive understanding.

Here are a few examples of the kinds of tricks you’ll receive:

Python
# How to merge two dictionaries
# in Python 3.5+:

>>> x = {'a': 1, 'b': 2}
>>> y = {'b': 3, 'c': 4}
>>> z = {**x, **y}
>>> z
{'c': 4, 'a': 1, 'b': 3}

# In Python 2.x you could use this:

>>> z = dict(x, **y)
>>> z
{'a': 1, 'c': 4, 'b': 3}
Python
# Why Python Is Great:
# Function argument unpacking

def myfunc(x, y, z):
    print(x, y, z)

tuple_vec = (1, 0, 1)
dict_vec = {'x': 1, 'y': 0, 'z': 1}

>>> myfunc(*tuple_vec)
1, 0, 1

>>> myfunc(**dict_vec)
1, 0, 1
Python
# The lambda keyword in Python provides a
# shortcut for declaring small and
# anonymous functions:

>>> add = lambda x, y: x + y
>>> add(5, 3)
8

# You could declare the same add()
# function with the def keyword:

>>> def add(x, y):
...     return x + y
>>> add(5, 3)
8

# So what's the big fuss about?
# Lambdas are *function expressions*:
>>> (lambda x, y: x + y)(5, 3)
8

# → Lambda functions are single-expression
# functions that are not necessarily bound
# to a name (they can be anonymous).

# → Lambda functions can't use regular
# Python statements and always include an
# implicit `return` statement.

Improve Your Python Skills, Bit by Bit:

🐍 Python Tricks 💌

Get a short & sweet Python Trick delivered to your inbox every couple of days. No spam ever. Unsubscribe any time. Curated by the Real Python team.

Python Tricks Dictionary Merge

What Python Devs Are Saying:

love the work you’ve done, are doing, and continue to do!
— Kenneth ☤ Reitz, Creator of the Requests library

“Python Tricks” curated by Dan Bader and the Real Python team.