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Hii, I'm Shreyash

and

This is Numpy

Let's import Numpy

import numpy as np

Make an array in numpy specifying the data type

Numpy suppports different types of data type to make our data sufficient enogh Like int8, int16, int32, int64

a=np.array([1, 3, 3], dtype='int8')
print(a)

[1 3 3]

Multidimensional Array

b=np.array([[1, 3, 5], [2, 3, 5]])
print(b)

[[1 3 5]
 [2 3 5]]

Shape of the array changing

Make sure the size of the array remains same in sort no element would be inserted or deleted during this process

b.shape=(1,6)
print(b)

[[1 3 5 2 3 5]]

b.shape=(3, 2)
print(b)

[[1 3]
 [5 2]
 [3 5]]

To know the data type of the numbers or data rather the array is containing

print(a.dtype)

int8

Size of the entire array

These are the two ways to this arraysize*itemsize or by using nbytes.

print(a.size*a.itemsize, 
a.nbytes)

3 3

Accesign info in the array using :o

[Start Index: End Index: Step Size]

b[2, :]

array([3, 5])

Repeat Things in the array

In below code array b is being repeated 3 times with the axis 1 meaning it will make array of size [1, 9]

b=np.array([[1, 2, 3]])
c=np.repeat(b, 3, axis=1)
print(c[0, ::2])

[1 1 2 3 3]

filling an array with random values

The below code does create random decimal numbers using random module in numpy of size [4, 2]

For random Int can use np.random.randint(val1, val2, size=(x,y)) where val1 is lowerbound , val2 is upperboud and size=(x, y) specifies an array to be made.

b[:, ::1]=[[1, 4, 5]]
d=np.random.rand(4,2)
print(d)

[[0.42195762 0.86498204]
 [0.91341263 0.33204442]
 [0.75985235 0.28298197]
 [0.69252822 0.57118244]]

Full to fill the Araay with some values

Full takes in the array b here or it can also take size you can specify as (x, y) insted

This array b's 2nd element of the array would be full of 4 meaning that the array that his makes would be taking the

Ask someone about it.

c.shape=(3, 3)
x=np.full(c[1, ], 4)
print(c, " and ",x)

[[1 1 1]
 [2 2 2]
 [3 3 3]]  and  [[[4 4]
  [4 4]]

 [[4 4]
  [4 4]]]

Excercise: Create this array

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