How to Sort a List in Python

Python provides a number of ways to sort a list. In this article, we’ll take a look at how to sort a list in Python using the built-in sorted() function.

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Sorting lists in Python – the basics

In Python, there are a few ways to sort a list. The first is to use the built-in sorted() method, which takes a list and returns a new list with the same elements in sorted order. The second is to use the list.sort() method, which sorts a list in place (i.e., it doesn’t create a new list).

The syntax for both methods is roughly the same:

sorted(list): Returns a new sorted list from the elements in the given list.
list.sort(): Sorts the elements of the given list in place (i.e., it doesn’t create a new list).
Both methods accept an optional key argument that can be used to specify a function that will be called on each element of the list before sorting. This is useful if you want to sort by something other than the element’s natural order, such as its length or alphabetical order.

Here are some examples of using these methods to sort lists:

sorted([3, 1, 2]): [1, 2, 3]
[3, 1, 2].sort(): [1, 2, 3]
sorted([‘c’, ‘a’, ‘b’]): [‘a’, ‘b’, ‘c’]
[‘c’, ‘a’, ‘b’].sort(): [‘a’, ‘b’, ‘c’]
You can also reverse the order of a sorted list by passing the reverse=True argument to either method:

sorted([3, 1, 2], reverse=True): [3, 2, 1] # Results are reversed
[3, 1

The sort() method

Python’s built-in sorted() function is very useful for creating new sorted lists from existing iterables. But what if you want to sort a list of objects by an attribute of the objects? That’s where the handy sorted() method comes in.

The sort() method is similar to sorted(), but it sorts the list in place rather than creating a new list. It accepts two arguments:

– reverse (optional): If True, reverse the sorting order (default is False).
– key (optional): A function that takes a single argument and returns a key to use for sorting purposes. This can be any function that returns a value that can be compared with other values (e.g., len() or str.lower()).

Here’s a simple example that sorts a list of strings by their length:

The sorted() function

The sorted() function returns a sorted list from the items in an iterable. You can optionally pass in a key function to sort by object property, instead of the default comparison.

The sorted() function is stable, meaning it will preserve the original order of equal elements in the iterable. To sort in reverse, use the reversed() function.

To sort a list of objects by an object property, you can use the list.sort() method. This method sorts the list in-place, meaning it doesn’t make a copy. To sort a list of objects by an object property in reverse, you can use the reversed() function with the list.sort() method.

The key parameter

When you sort a list in Python, you can use the key parameter to specify a function that will be used to determine how the list should be sorted. The function should take a single element from the list and return a value that will be used to determine the sort order.

For example, if you have a list of strings, you can use the len function as the key to sort the list by string length:

sorted(strings, key=len)

You can also use lambda functions as keys:

sorted(strings, key=lambda s: s.lower())

The reverse parameter

The `reverse` parameter is used to sort the list in reverse order. When set to `True`, the list is sorted in reverse order. The default value is `False`.

The cmp parameter

Python’s sort() function has a number of options that can be specified in order to customize how the list is sorted. One option is the cmp parameter, which allows you to specify a comparison function.

The cmp function takes two parameters, x and y, and returns a negative value if x < y, 0 if x == y, or a positive value if x > y. In Python 3, the cmp parameter has been removed and replaced with the key parameter, which allows you to specify a function that transforms each element before comparisons are made.

To sort a list in reverse order, you can specify reverse=True as a parameter to the sort() function. You can also combine this with the key and/or cmp parameters to further customize how the list is sorted.

The stable parameter

The stable parameter is a boolean parameter. If True (the default), the list is guaranteed to be stable: equal elements will retain their relative order. If False, the list may not be stable.

Sorting nested lists

Sorting a list is one of the most fundamental operations you can perform on a sequence in Python. In fact, it is so fundamental that the methods for doing so are built into the language itself. The sort() method is used to sort a list in-place, and the sorted() function returns a sorted copy of a given iterable (list, tuple, etc.).

The simplest form of sorting is to take a list and return a new list with the same elements in sorted order. The most common way to do this is with the built-in function sorted(), which takes any iterable as an argument and returns a list:

>>> my_list = [3, 5, 1, 4, 2]
>>> sorted(my_list)
[1, 2, 3, 4, 5]
Very often you will want to sort a list of lists by some criteria. For example, let’s say you have a list of tuples where each tuple represents a person’s name and age. You want to sort this list of tuples by age so that the people are listed in order from youngest to oldest.

Luckily, Python’s sorted() function makes this easy for us. All we need to do is specify how we want our list of tuples to be sorted. We do this by providing a “key” function as an argument to sorted(). This key function takes in one element from our list and returns another value that will be used in the sorting process. In our case, we want to sort by age so we’ll just return each person’s age:

>>> people = [(‘Alice’, 32), (‘Bob’, 48), (‘Charlie’, 28)]
>>> sorted(people, key=lambda person: person[1]) # sort by age
[(‘Charlie’, 28), (‘Alice’, 32), (‘Bob’, 48)]

Sorting in place

The easiest way to sort a list in-place is with the list.sort() method. This method modifies the list in-place and returns None to prevent potential confusion – if you want to return a sorted list, use sorted(list).

To use this method, simply call it on a list, with an optional “reverse” Boolean parameter to sort in reverse (descending) order:

The sorted() method for custom objects

The sorted() method takes a positional argument and an optional keyword argument. The positional argument is the list that you want to sort, and the keyword argument is the key= function that you want to use to sort the list. The sorted() method returns a new sorted list.

The sorted() method is very flexible. You can use it to sort a list of numbers, strings, or even tuples. You can also use it to sort a list of custom objects. To do this, you need to pass in a key= function that tells Python how to sort your objects.

For example, let’s say you have a list of objects that represent different people. Each person has a first name, last name, and age. You want to sort this list by last name. Here’s how you would do it:

people = [
{‘first_name’: ‘John’, ‘last_name’: ‘Smith’, ‘age’: 30},
{‘first_name’: ‘Jane’, ‘last_name’: ‘Doe’, ‘age’: 25},
{‘first_name’: ‘Joe’, ‘last_name’: ‘Bloggs’, ‘age’: 20}
]

def get_last_name(person):
return person[‘last_name’]

sorted(people, key=get_last_name)

##Title: How to Make Homemade Bread
##Heading: The difference between white and wheat flour

##Keywords: Flour types, all-purpose flour, protein content

##Expansion: All-purpose flour is made from a blend of hard and soft wheat flours and generally contains between 10% and 12% protein. It’s frequently used in quick breads, cakes, cookies, pizzas, pancakes, waffles, some muffins, some pastries (including pie crusts), some fried foods (such as tempura), some sauces (such as roux), some batters (such as for coating chicken fingers), and as a Thickener for gravy or soup. All-purpose flour can be stored in an airtight container for up to six months in the pantry; stored in the fridge or freezer, it will keep up to one year.

Wheat flour is milled from hard wheat berries and contains more protein than all-purpose flour—between 13% and 16%. Bread flour also has a higher gluten content than all-purpose flour—gluten is what gives bread its distinctive chewy texture (think bagels or pizza crust). Because of its high gluten content, bread flour is typically used for yeast breads like rolls, bagels, pizza dough, and sandwich loaves; it can also be used for certain quick breads like anger chestnut cake or oatmeal date nut bread where additional gluten gives the finished product more structure.

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