Can i do if or or statement in python?
Watch Now This tutorial has a related video course created by the Real Python team. Watch it together with the written tutorial to deepen your understanding: Using the Python or Operator Show
There are three Boolean operators in Python: By the end of this tutorial, you’ll have learned:
You’ll learn how to use the Python Boolean LogicGeorge Boole (1815–1864) developed what is now called Boolean algebra, which is the foundation of the digital logic behind computer hardware and programming languages. Boolean algebra is built around the truth value of expressions and objects (whether they are true or false) and
is based in the Boolean operations With the help of Boolean logic, you can evaluate conditions and decide what operations your programs will execute, depending on the truth value of those conditions. This is an important cornerstone in programming and provides you with the tools to decide the execution flow of your programs. Let’s take a look at some of the basic concepts related to Boolean logic in Python:
Now that you have a better context on Boolean logic, let’s proceed with some more Python-specific topics. The Python Boolean OperatorsPython has three Boolean operators that are typed out as plain English words:
These operators connect Boolean expressions (and objects) to create compound Boolean expressions. The Python Boolean operators always take two Boolean expressions or two objects or a combination of them, so they’re considered binary operators. In this tutorial, you’ll be covering the Python How the Python or Operator WorksWith the Boolean This is the general logic behind the Using or With Boolean ExpressionsYou’ll
need two subexpressions to create a Boolean expression using the Python
If at least one of the subexpressions ( Here’s a summary of the Python
Table 1. Logical Python This table summarizes the resulting truth value of a Boolean expression like Let’s illustrate the resulting truth values shown in Table 1 by coding some practical examples: >>>
In the previous
examples, whenever a subexpression is evaluated to Using or With Common ObjectsIn general, the operands of an expression involving an
If the operands involved in an This means that Python doesn’t coerce the result of an >>>
In the two first examples, the first operands ( In the last two
examples, the left operand is false (an empty object). The Python You can summarize the behavior shown in the previous code as follows:
Table 2. Python In short, the Python You can generalize this behavior by chaining several operations in a single expression like this: In this example, the Python Mixing Boolean Expressions and ObjectsYou can also combine Boolean expressions and common Python objects in an
Table 3. Python Let’s see how this works with some examples: >>>
In Case 1 and Case 2, the subexpression As an exercise, you could try to extend Table 3 by reversing the order of the expressions in the third column, that is, use Short-Circuit EvaluationPython can sometimes determine the truth value of a Boolean expression before it has evaluated all the subexpressions and objects involved. The Python >>>
If the first operand in an Let’s consider another example: >>>
In Case 1, Python evaluated Case 2 evaluates both functions, because the first operand ( Case 3 evaluates both
functions, because both return In Case 4, Python only evaluates the first function, which is In short-circuit (lazy) evaluation, the second operand on a Boolean expression is not evaluated if the value of the expression can be determined from the first operand alone. Python (like other languages) bypasses this second evaluation in favor of performance, because evaluating the second operand would be an unnecessary waste of CPU time. Finally, when it comes to performance when you’re using the Python
Section RecapYou’ve learned how the Python Before that, let’s recap some important points about
Now it’s time to learn where and how you can use this operator with the help of some examples. Boolean ContextsIn this section, you’ll see some practical examples of how to use the Python There are two main situations where you can say you’re working in a Boolean context in Python:
With an On the other hand, These two structures are part of what you’d call control flow statements. They help you decide your programs’ execution path. You can use the Python if StatementsLet’s say you want to make sure that one of two conditions (or both) is true before you choose a certain path of execution. In this case, you can use the Python Suppose you need to get a confirmation from the user to run some actions depending on the user’s answer: >>>
Here, you get the user’s input and assign it to In the first call to
Another example could be when you’re trying to determine whether a number is outside a range. In this case, it’s also possible to use the Python >>>
When you call On the other hand, while Loops
Suppose you need to measure the operating temperature of some industrial equipment until it gets into a range of 100 ºF to 140 ºF. To do so, you can use a
This is a toy example almost in pseudo code, but it illustrates the idea. Here, the Non-Boolean ContextsYou can take
advantage of the special features of the Python Notice that the logical operators ( >>>
Here, the You can take advantage of this somewhat special behavior of Default Values for VariablesOne common way to use the Python >>>
Here, you assigned to You can also use this feature to assign a default value to your variables. The following example sets In the previous code,
you assign Default return ValuesYou can manipulate the If you supply an empty iterable to >>>
The default behavior of Mutable Default ArgumentsA common problem beginner Python programmers face is to try to use mutable objects as default arguments to functions. Mutable values for default arguments can retain state between calls. This is often unexpected. It happens because default argument values are evaluated and saved only once, that is, when the Consider the following example: >>>
Here, every call to If that’s not the behavior you want, then the traditional (and safest) solution is to move the default to the body of the function: >>>
With this
implementation, you are ensuring that The >>>
However, this isn’t exactly the same. For example, if an empty If you are pretty sure that you’ll only be using non-empty Zero DivisionZero division can be a common problem when you’re dealing with numeric calculations. To avoid this problem, it’s likely that you end up checking if the denominator is equal to Let’s take a look at an example: >>>
Here, you tested if the denominator ( >>>
In this case, the Python The difference with the previous example is that, if Multiple Expressions in lambdaPython provides The most common pattern for you to
write a >>>
With this example, you’ve forced When In this case, the value returned by the Boolean expression is also the value returned by >>>
Here, ConclusionYou now know how the Python Now that you know the basics of the
Python
In addition, you’ve learned a little bit about Boolean logic, as well as some of its main concepts in Python. Watch Now This tutorial has a related video course created by the Real Python team. Watch it together with the written tutorial to deepen your understanding: Using the Python or Operator Can you use if and/or together in Python?Complex conditions in Python's if statements: and + or. To handle complex scenarios, our if statement can combine the and and or operators together.
Can there be 2 IF statements in Python?It works that way in real life, and it works that way in Python. if statements can be nested within other if statements. This can actually be done indefinitely, and it doesn't matter where they are nested. You could put a second if within the initial if .
Can we use two conditions in if statement?Use two if statements if both if statement conditions could be true at the same time. In this example, both conditions can be true. You can pass and do great at the same time. Use an if/else statement if the two conditions are mutually exclusive meaning if one condition is true the other condition must be false.
How do you combine two conditions in Python?If we want to join two or more conditions in the same if statement, we need a logical operator. There are three possible logical operators in Python: and – Returns True if both statements are true. or – Returns True if at least one of the statements is true.
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