Python Tips and Tricks

# __repr__ vs __str__

How a python Class is represented as a string also how is represented, when you interact with the object.Instead of building your own to-string conversion machinery you’ll be better off adding the __str__ and __repr__ “dunder” methods
to your class. They are the Pythonic way to control how objects are
converted to strings in different situations

Notes:

str = easy to read representation of the class

repr = unambiguos more ment for developers

Example

import datetime

date = datetime.date.today()

> str(date)
>'2017-07-11'
> repr(date)
'datetime.date(2017, 7, 11)'

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# The get() method on dicts
# and its "default" argument

name_for_userid = {
    382: "Alice",
    590: "Bob",
    951: "Dilbert",
}

def greeting(userid):
    return "Hi %s!" % name_for_userid.get(userid, "there")

>>> greeting(382)
"Hi Alice!"

>>> greeting(333333)
"Hi there!"