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We have covered the basic data types and advanced data types in python in our previous blog posts.. In this blog, the conditional statements will be covered. If you are new to Python, please start from the first blog post to get a better understanding of this blog.

Conditional statements in Python 鈥� table of contents:

1. Conditional statements in Python 鈥� what do they do?
2. Python input()
3. If statement in Python
4. Syntax in Python
5. If else in Python

Conditional Statements in Python 鈥� what do they do?

The conditional statements in Python regulate the flow of the code execution. In a very layman term, these statements are used when you want the program to do a task if a condition is satisfied and not to do the same task when the condition is not fulfilled.

Python input()

Up till now, we have just printed out the output but never gave any input to our program. In Python input() is used for giving input to the program in python. The example is illustrated below.

For Example:

# Take input
x=input()
print(x)

The above code will ask for an input which will be stored in the X variable for further usage.

Output:
5
5

The input can also have a string query in it. The example is illustrated below.

# Take input
x=input(鈥減lease enter your age?鈥�)
print(x)

Output:
please enter your age. 5
5

Even the input can be modified using the datatype functions used in the typecast of a datatype. The example is illustrated below.

# Take input
x=int(input(鈥減lease enter your age?鈥�))
y=input(鈥減lease enter your age?鈥�)
print(type(x))
print(type(y))

Output:
please enter your age. 5
please enter your age. 5
<class 鈥榠nt鈥�>
<class 鈥榮tr鈥�>

In the above example, we can see that the input without any typecast function is a string value. Hence, the default value for input is string.

If statement in Python

If a program has only a single decision to make, then one 鈥渋f鈥� statement is used. Let鈥檚 take an example where we want to allow a person only if he or she has a mask.

#if statement
mask=True
if mask==True:
 print(鈥渢he person can enter鈥�)

Syntax in Python

The syntax is quite simple, it鈥檚 followed by the condition and indentation of one tab space whenever there is something in the if statement. When we discussed the operators in the variables blog. We discussed comparison operators, logical operators, and mathematical operators.

In this condition, both comparison operators and logical operators can be used. In the above example, we can see that we used 鈥�==鈥� operator for comparison. In the above program if the mask is True then the statement will be printed otherwise it will not print anything.

Let鈥檚 execute the program and examine the output.

Output:
the person can enter

What will happen if we change the make value to False? The output will be as given below. Which is empty 鈥� nothing will be printed as the condition is not fulfilled.

Output:

If else in Python

In the above example, we just have a condition, which says if a person has mask they can enter. But there is not otherwise, what to do if the person doesn鈥檛 have a mask. Hence it seems to be an incomplete program. Let鈥檚 say if they don鈥檛 have a mask, we want them to get a mask to enter. For this we will be using else statement which executes only when the 鈥渋f鈥� statement condition is not fulfilled.

Example is illustrated below.

#if else statement
mask=True
if mask==True:
 print(鈥渢he person can enter鈥�)
else:
 print(鈥減lease, get a mask to enter鈥�)

Now if we change the value of the mask to False, then we will get 鈥減lease, get a mask to enter鈥�)

#if else statement

mask=False

if mask==True:
 print(鈥渢he person can enter鈥�)
else:
 print(鈥減lease, get a mask to enter鈥�)

Output:
please, get a mask to enter

This can also be written in the below format.

#if else statement

mask=False

if mask==True:
 print(鈥渢he person can enter鈥�)
print(鈥減lease, get a mask to enter鈥�)

In , whenever you write a statement after the if without indentation, it taken to be under else statement.

Now let鈥檚 add a case, where if a person doesn鈥檛 have a mask but is willing to buy it , can buy the mask from the guard itself and enter. For this we will change our earlier code a bit. We will give string values such as 鈥渘obuy鈥� ,鈥漛uy鈥�, 鈥測es鈥�. Now we will use these to write our if statements.

#if else statement

mask=

if mask==鈥漼es鈥�:
 print(鈥渢he person can enter鈥�)
elif mask==鈥漛uy鈥�:
 print(鈥減erson bought the mask and can enter鈥�)
print(鈥減lease, get a mask to enter鈥�)

Now the according to the mask value, the execution will be done. If the mask value is 鈥渘obuy鈥�, we will get the output to be 鈥減lease, get a mask to enter鈥�.

#if else statement

mask=鈥漬obuy鈥�

if mask==鈥漼es鈥�:
 print(鈥渢he person can enter鈥�)
elif mask==鈥漛uy鈥�:
 print(鈥減erson bought the mask and can enter鈥�)
print(鈥減lease, get a mask to enter鈥�)

Output:
please, get a mask to enter

Even if the mask is given any other value, we will get the result to be 鈥減lease, get a mask to enter鈥�. This is because above two if statement conditions will not be fulfilled.

#if else statement
mask=鈥漼es鈥�

if mask==鈥漼es鈥�:
 print(鈥渢he person can enter鈥�)
elif mask==鈥漛uy鈥�:
 print(鈥減erson bought the mask and can enter鈥�)
print(鈥減lease, get a mask to enter鈥�)

For 鈥測es鈥� value in mask, the output will be 鈥渢he person can enter鈥�.

#if else statement
mask=鈥漼es鈥�

if mask==鈥漼es鈥�:
 print(鈥渢he person can enter鈥�)
elif mask==鈥漛uy鈥�:
 print(鈥減erson bought the mask and can enter鈥�)
print(鈥減lease, get a mask to enter鈥�)

Output:
the person can enter

For 鈥渂uy鈥� in the mask, the output will be (鈥減erson bought the mask and can enter鈥�).

#if else statement
mask=鈥漼es鈥�
if mask==鈥漼es鈥�:
 print(鈥渢he person can enter鈥�)
elif mask==鈥漛uy鈥�:
 print(鈥減erson bought the mask and can enter鈥�)
print(鈥減lease, get a mask to enter鈥�)

Output:
the person bought the mask and can enter

In this blog, we have covered some basics of conditional statements in , the further topics on functions will be covered in the next blog post. From this blog onward, the reader will be given some practice questions, the answers will be available in the next blog for the questions in this blog.

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