In programming, a switch statement is a control structure used to decide which of multiple possible actions to take, depending on some criterion. The switch statement is a succinct and effective method of implementing several branches of execution in various computer languages, such as Java and C. However, Python does not have native support for the switch statement.
You can mimic the behavior of Python’s switch statement with an if statement. With the help of the if statement, you can choose which blocks of code to run depending on the outcome of a conditional test. To provide switch case functionality for instance, you may use an if statement, as was demonstrated previously.
When there are many possible outcomes, the if statement can become too lengthy and difficult to comprehend to serve as a substitute for a switch statement in Python. If you need a more powerful and understandable switch statement in Python, you may build it with dictionaries or classes.
Here’s an example using dictionaries to implement a switch statement in Python:
def switch_case(case_value):
# Define a dictionary with the case values as keys and the corresponding functions as values
cases = {
1: case1,
2: case2,
3: case3,
4: case4,
5: case5
}
# Use the get method to get the function corresponding to the case value
func = cases.get(case_value, default_case)
func()
def case1():
print("Case 1")
def case2():
print("Case 2")
def case3():
print("Case 3")
def case4():
print("Case 4")
def case5():
print("Case 5")
def default_case():
print("Default case")
# Call the function with different case values
switch_case(1) # Output: Case 1
switch_case(2) # Output: Case 2
switch_case(3) # Output: Case 3
switch_case(4) # Output: Case 4
switch_case(5) # Output: Case 5
switch_case(6) # Output: Default case
Disadvantages of a Switch statement in Python
In Python, implementing a switch statement using a dictionary or a class provides several benefits over using an if statement, but it also has some drawbacks.
- Due to the lack of a built-in switch statement, Python might be difficult to understand for inexperienced programmers.
- Complication: When dealing with a large number of choices, the dictionary or class-based way to construct a switch statement in Python might result in greater complexity and lengthier code.
- Since the get function must execute a dictionary lookup for each case value, the dictionary-based technique can be less efficient than a switch statement in some other programming languages.
- Python’s implementation of a switch statement, which relies on a dictionary and classes, is less powerful than the switch statements in other languages. For instance, range checks cannot be executed like they can in a Java or C switch statement.
- Keeping up with the ever-evolving list of possible solutions might be a challenge when you’re responsible for maintaining a huge dictionary or class hierarchy.
- Even with these drawbacks, implementing a switch statement in Python with dictionaries or classes can still be a more efficient and understandable alternative than utilizing an if statement. Depending on the needs of your application and your familiarity with the available options, pick the method that works best for you.
5 best alternatives of Switch case in Python
Dictionary-based approach: The dictionary technique is a more efficient and understandable way to build a switch statement in Python since it allows you to map case values to functions.
Class-based approach: Another option is to use classes to mimic a switch statement in Python. By doing so, you may leverage the class hierarchy to achieve the functionality of a switch statement, one class per possible action.
If-elif-else statement: A switch statement in Python may be written using the familiar if-elif-else structure. This method is simple, but it can quickly become unmanageable when faced with a huge number of options.
Function objects: Python’s switch statement may also be implemented with the help of function objects. For each possible outcome, you may write its own function and then invoke it using the case value.
Lambda functions: When writing code in Python, lambda functions can be used as an alternative to the switch case. A lambda function representing each possible outcome may be defined in this method, and then the relevant function is invoked depending on the case value. For cases with few possible selections, this method may be used to streamline the code and improve readability.
Let’s discuss mow in detail
Dictionary-based approach
In Python, a common alternative to the switch case is the dictionary-based technique. When you use this method to implement a switch statement in Python, you can map case values to functions. This is a better and easier way to do this than other methods.
The following is an explanation of how you can put the dictionary-based strategy into action:
- Define a dictionary with the case values as keys and the corresponding functions as values.
def case1():
print("Case 1")
def case2():
print("Case 2")
def case3():
print("Case 3")
def default_case():
print("Default case")
cases = {
1: case1,
2: case2,
3: case3
}
- 2. Use the get method to retrieve the function corresponding to the case value.
def switch_case(case_value):
func = cases.get(case_value, default_case)
func()
3. Execute the function if it is present in the dictionary. If the case value is not present in the dictionary, you can execute a default function.
switch_case(1) # Output: Case 1 switch_case(2) # Output: Case 2 switch_case(3) # Output: Case 3 switch_case(4) # Output: Default case
In Python, when there are many possible outcomes to a switch statement, the dictionary-based technique is the most effective and legible way to implement it. It provides a clear and straightforward implementation of a switch statement in Python by enabling you map case values to functions and then fetch the matching function using the get method.
Class Based Approach
Another common substitution for Python’s switch case is the use of classes. By doing so, you may leverage the class hierarchy to achieve the functionality of a switch statement, one class per possible action.
Here’s how you can implement the class-based approach:
- Define a base class for the switch statement and an abstract method that each alternative must implement.
class SwitchCase:
def execute(self):
pass
class Case1(SwitchCase):
def execute(self):
print("Case 1")
class Case2(SwitchCase):
def execute(self):
print("Case 2")
class Case3(SwitchCase):
def execute(self):
print("Case 3")
class DefaultCase(SwitchCase):
def execute(self):
print("Default case")
2. Create a dictionary that maps case values to the corresponding classes.
cases = {
1: Case1,
2: Case2,
3: Case3
}
3. Use the get method to retrieve the class corresponding to the case value, and then create an instance of the class.
def switch_case(case_value):
cls = cases.get(case_value, DefaultCase)
cls().execute()
4. Call the execute method on the instance of the class to execute the corresponding alternative.
switch_case(1) # Output: Case 1 switch_case(2) # Output: Case 2 switch_case(3) # Output: Case 3 switch_case(4) # Output: Default casePython’s switch statement may be implemented more systematically using a class-based approach. It’s a clean and manageable approach to construct a switch statement in Python since you can declare a class for each alternative and then utilise the class hierarchy to implement the functionality of a switch statement.
If-elif-else statement based Approach
It is possible to understand the behavior of Python’s switch statement by using the if-elif-else control flow statement.
Using an if-else-if-else sentence is as simple as the following:
def switch_case(case_value):
if case_value == 1:
print("Case 1")
elif case_value == 2:
print("Case 2")
elif case_value == 3:
print("Case 3")
else:
print("Default case")
In an if statement, we first see if the case value equals the first possible option. Using the elif statement, we may go on to the next possible value if the case value doesn’t match the first. The else statement is used to run the fallback scenario if no other options are applicable.
switch_case(1) # Output: Case 1 switch_case(2) # Output: Case 2 switch_case(3) # Output: Case 3 switch_case(4) # Output: Default casePython’s if-else-if statement makes it easy to write a switch statement. It enables you to examine numerous conditions and act on the results of the first one to return True. However, the if-elif-else sentence may grow complicated and hard to maintain if there are many possible outcomes.
Using Function objects
Another common alternative to the switch case methodology seen in Python is the function object technique. Within the context of this strategy, it is possible to define a function for each available option, after which the functions may be saved within a list or a dictionary.
Here is how you may put the strategy of using function objects into action:
- Define a function for each alternative.
def case1():
print("Case 1")
def case2():
print("Case 2")
def case3():
print("Case 3")
def default_case():
print("Default case")
2. Create a list or a dictionary that maps case values to the corresponding functions.
cases = {
1: case1,
2: case2,
3: case3
}
3. Use the get method to retrieve the function corresponding to the case value.
def switch_case(case_value):
func = cases.get(case_value, default_case)
func()
4. Call the function to execute the corresponding alternative.
switch_case(1) # Output: Case 1 switch_case(2) # Output: Case 2 switch_case(3) # Output: Case 3 switch_case(4) # Output: Default caseUsing a function object to implement a switch statement in Python provides an organised and reusable solution. One may design a function for each possible outcome, collect them in a list or dictionary, and then invoke the appropriate function depending on the case value. When dealing with a high number of options while yet maintaining an easily manageable codebase, this strategy is quite handy.
Lambda functions
Concisely implementing a switch statement in Python may be done with the lambda function technique. Using anonymous functions (lambda functions) to define each possibility and then storing the resulting functions in a set or dictionary is one possible implementation of this strategy.
The lambda function method may be applied as follows:
- Create a lambda function to represent each potential solution.
case1 = lambda: print("Case 1")
case2 = lambda: print("Case 2")
case3 = lambda: print("Case 3")
default_case = lambda: print("Default case")
2. Create a list or a dictionary that maps case values to the corresponding functions.
cases = {
1: case1,
2: case2,
3: case3
}
3. Use the get method to retrieve the function corresponding to the case value.
def switch_case(case_value):
func = cases.get(case_value, default_case)
func()
4. Call the function to execute the corresponding alternative.
switch_case(1) # Output: Case 1 switch_case(2) # Output: Case 2 switch_case(3) # Output: Case 3 switch_case(4) # Output: Default caseUtilizing lambda functions in place of a switch statement is a lean and mean method of coding in Python. You may construct anonymous functions for each possible outcome, collect them in a set or dictionary, and then access them via the case value. This method is helpful if you value code readability and compactness but yet want to reap the benefits of employing functions.
Conclusion
In this article, we will learn how to use a Switch Case in Python. You may now test out the python switch case in your own code. It improves code efficiency and is simple to apply, hence its usage is strongly suggested.
Many programming languages make use of the “switch case” statement to manage the execution of a programme. However, the “switch case” expression is not directly analogous in Python. A number of alternate strategies exist that may be employed to accomplish the same goals. Examples of these alternatives include the use of if-else expressions, dictionaries, classes, function objects, and lambda functions. There are benefits and drawbacks to each methodology; picking the right one depends on the nature of the problem at hand.
In Python, it is possible to create code with switch-like behaviour by use statements like if, elif, and else. Writing a sequence of if-elif conditions to test for different values of a variable and then running different code blocks depending on the value of that variable is what this method is all about. The dictionary-based strategy is another option; in this scenario, a dictionary data structure is used to map switch case values to their respective functions or code blocks.
To use a class-based approach, one must first create a class containing methods that embody the desired switch-like behaviour. In this method, a new instance of the class is created, and then the relevant method is invoked based on the value of a variable. In Python, you may achieve the same switch-like functionality by utilising function objects or lambda functions.
Ultimately, the needs of the situation at hand will dictate which of these options is selected. The Python programming language offers a number of different ways to perform switch-like behaviour and regulate the flow of a programme, including the if-elif-else statement, a dictionary-based approach, a class-based approach, function objects, and lambda functions.
