{"id":22123,"date":"2020-09-04T09:55:02","date_gmt":"2020-09-04T16:55:02","guid":{"rendered":"https:\/\/careerkarma.com\/blog\/?p=22123"},"modified":"2023-12-01T03:59:23","modified_gmt":"2023-12-01T11:59:23","slug":"python-switch","status":"publish","type":"post","link":"https:\/\/careerkarma.com\/blog\/python-switch\/","title":{"rendered":"Python Switch Statement: A How-to Guide"},"content":{"rendered":"\n

Unlike Java or C#<\/a>, Python does not have a built-in switch statement. This means you cannot evaluate a switch expression without having to write your own code that mimics a \u201cswitch…case\u201d statement.
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In this guide, we discuss how to write a \u201cswitch…case\u201d in Python, and walk through two examples of a faux-switch statement so you can learn how to write one in your code.<\/p>\n\n\n\n

Switch Statements: A Refresher<\/h2>\n\n\n\n

A switch statement lets you select one of a set of code blocks to run. They are a way of evaluating multiple expressions in a program.
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A switch statement works by evaluating a switch statement and comparing the result of that statement with values in \u201ccase\u201d statements. If a match is found, the respective block of code is run. Otherwise, nothing will happen.
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Optionally, a \u201cdefault\u201d keyword is used to run a block of code if no statement is found that matches a particular expression.<\/p>\n\n\n\n

Python Switch Statement: Returning Individual Values<\/h2>\n\n\n\n

Let\u2019s write a program that converts a numerical value to a day of the week.
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To start, ask a user to insert a number<\/a> they want to convert into a written day:<\/p>\n\n\n\n

convert_to_day = int(input("Insert a day of the week: "))<\/pre><\/div>\n\n\n\n
We convert the value the user inserts into our program to an integer. We\u2019ll discuss why this is necessary later in the tutorial.
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Next, we define a dictionary<\/a>. This dictionary will contain all the days of a week. Each key will store a day as a number and each value will store a day written out (i.e. Tuesday):
<\/p>\n\n\n\n
days = {\n\t   1: "Monday",\n\t   2: "Tuesday",\n\t   3: "Wednesday",\n\t   4: "Thursday",\n\t   5: "Friday",\n\t   6: "Saturday",\n\t   7: "Sunday"\n}<\/pre><\/div>\n\n\n\n
There are seven keys and values in our dictionary. The key \u201c1\u201d represents \u201cMonday\u201d and so on until the final day of the week.
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Next, we use the dictionary get() method<\/a> to access the item in this dictionary that corresponds with the value a user has inserted:
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day_as_written = days.get(convert_to_day, "There is no day with this numerical value.")\nprint(day_as_written)<\/pre><\/div>\n\n\n\n
We\u2019ve converted the value a user inserted into our program to an integer so we can use it in our get()<\/code> statement. If there is no key equal to the value that \u201cconvert_to_day\u201d stores, our code will return \u201cThere is no day with this numerical value.\u201d
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If a user inserts the value \u201c1\u201d, our code will evaluate:
<\/p>\n\n\n\n
days[1]<\/pre><\/div>\n\n\n\n
This will retrieve the value associated with the key \u201c1\u201d in our list.
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Let\u2019s run our code and see what happens:
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Insert a day of the week: 1\nMonday<\/pre><\/div>\n\n\n\n
Our code successfully converts the number a user inserts to a string. Let\u2019s run our code on a day that does not exist in our dictionary:
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Insert a day of the week: 8\nThere is no day with this numerical value.<\/pre><\/div>\n\n\n\n
Our code works even if a user inserts an invalid value.<\/p>\n\n\n\n
Python Switch Statement: Calling Functions<\/h2>\n\n\n\n
We can use this syntax to call functions in our code<\/a>. We\u2019re going to build an application that displays information about a list of purchases at a sandwich store.
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First, let\u2019s define a list of purchases:
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purchases = [2.50, 2.50, 2.75, 3.90, 5.60, 2.40]<\/pre><\/div>\n\n\n\n
Next, define three functions. These functions will calculate:
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