How Indentation works in Python

 Lets say we want to write a python program to check whether a variable has a value 10 or not.

Code : 

var = 10

if (var == 10):

print(' A is 10')

Error :

File "<ipython-input-53-61659dc01be1>", line 3

    print(' A is 10')
    ^
IndentationError: expected an indented block

>> As we can see above we get the above error. This means the print statement is not as per expected indentation. Lets see if put it in the right way like below :

var = 10
if (var == 10):
  print(' A is 10')

In above code i try to shift/move the print statement a bit towards right side with a couple of spaces it could also be possible with tab and it works fine now.

 A is 10
In [ ]:

It prints the expected statement now as above we can see the actual cell is displayed .

Lambda function in Python

To understand Lambda function we need to see a normal function in Python first, Lets begin:

Lets define a function first and then we will convert it to Lambda function

-----------------------
def add(x, y):
    return x + y

print(add(2, 3))
-----------------------

Above function name is add, it expects two arguments x and y and returns their sum. Notice how we are printing and calling add function in last line

The output of above program is below:

-----------------------
5
-----------------------

# Now let us convert this function to Lambda function in Python

----------------------------------
add = lambda x, y : x + y

print (add(2, 3))

----------------------------------

The output of above code is below :

--------------
5
--------------

So what on earth is Lambda then ?

Basically lambda function is used for creating small, one-time and anonymous function objects in Python. In lambda x, y: x + y; x and y are arguments to the function and x + y is the expression which gets executed and its values is returned as output. Lambda functions can be used wherever function objects are required. They are syntactically restricted to a single expression. Semantically, they are just syntactic sugar for a normal function definition. Like nested function definitions, lambda functions can reference variables from the containing scope.

Function in Python

We will now write a function in Python :

-----------------------
def add(x, y):
    return x + y

print(add(2, 3))
-----------------------

Above function name is add, it expects two arguments x and y and returns their sum. Notice how we are printing and calling add function in last line

The output of above program is below:

-----------------------
5
-----------------------

Python if Statement

Lets write a Python code where we see how if statement is used

-----------------------------------
num = 3
if num > 0:
    print(num, "is a positive number.")
print("This is always printed.")

num = -1
if num > 0:
    print(num, "is a positive number.")
print("This is also always printed.")

-----------------------------------

The output of above code will be below

-----------------------------------

3 is a positive number.

This is always printed.

This is also always printed.

-----------------------------------

Explanation of the code :- Watch how we use num variable 3 and print it as positive, notice the second time positive is not printed because -1 is negative not > 0

The range() Function in Python

Lets use Range function of Python to write below code to print range of numbers between 0 to 4

------------------------------
for i in range(5):
    print(i)

------------------------------

The output of above code will be :

------------------------------

0
1
2
3
4
------------------------------

Now lets use Range function again of Python to see another scenario where 10 is not printed in the range of 5,10 but 5 is printed so it includes first number not the last
------------------------------

for i in range(5,10):
     print(i)

------------------------------

The output of above code is below

------------------------------
5
6
7
8
9

------------------------------

The given end point is never part of the generated sequence; range(10) generates 10 values, the legal indices for items of a sequence of length 10. It is possible to let the range start at another number, or to specify a different increment (even negative; sometimes this is called the ‘step’):

So lets take a scenario of below code :

---------------------------------

for i in range(0,10,3):
    print(i)

---------------------------------

The output of above code is 

------------------------------

0

3

6

9

------------------------------