# Python NumPy append + 9 Examples

In this Python Numpy tutorial, we will discuss Python NumPy append with a few examples like below:

• Python NumPy append 2d array
• Python NumPy append to an empty array
• Python NumPy append row
• Python NumPy append column
• Python NumPy append two arrays
• Python NumPy append axis
• Python NumPy append array to array
• Python NumPy append an element to the array
• Python NumPy append not working

If you are new to NumPy, check Python Numpy to know how to use Python NumPy.

## Python NumPy append

• In this section, we will learn about Python NumPy append.
• The Numpy append method allows us to insert new values into the last of an existing NumPy array.
• This function always returns a copy of the existing numpy array with the values appended to the given axis.
• We will start by creating a new script with the NumPy library imported as np.
• Next, we will import a new numpy array called data or numbers by calling np.arange() and passing the value in the integer data type.
• This method will create a NumPy array with integers.
• Now we will easily use the append function by using np. append().
• It is used to append values to the end of a given numpy array.

Syntax:

Here is the Syntax of the numpy append function

``````numpy.append
(
arr,
values,
axis=None
)``````

Example:

Let’s take an example to check how the numpy append function is used in Python

``````import numpy as np

a = np.array([[1,2,3],[2,6,7]])
b = np.append(a,[6,7,8])
print(b)``````

Here is the Screenshot of the following given code.

You may like: Python NumPy zeros

## Python numpy append 2d array

• In this section, we will learn about python numpy append 2d array.
• The Numpy append function provides us to add new elements to the end of an existing numpy array.
• Two Dimensional Numpy array means the collection of data in lists of a list. It is also known as a matrix. In a 2D array, you have to use two square brackets that is why it said lists of lists.
• We will use a function np.reshape().This method will change the shape of the numbers numpy array into the given number of rows and columns.
• In NumPy append() 2dimension, we can easily use a function that is reshaping. This reshapes method allows a new shape to a numpy array without changing its data.

Syntax:

``````numpy.append
(
arr,
values,
axis=None
)``````
1. array: input array
2. values: values to be added in the array.
3. axis: axis along which we want to calculate the sum value.

Example:

``````import numpy as np
num = np.arange(4)

b = num.reshape(2,2)
num_2d = (np.append(b,[[4,5]],axis=0))
print(num_2d)``````

Here is the Screenshot of following given code

## Python numpy append to empty array

• In this section, we will learn about python NumPy append to an empty array.
• The Numpy append method allows us to insert new values to the end of an numpy array.
• To create an empty array in Python, we use the empty function. it returns an array of given shapes and types without initializing the entries of an array.
• It is very important to understand unlike zeros empty doesn’t set the array value to zero therefore the performance of the array will be faster than the zero function.
• It requires a user to manually set all the values of the array.
• Now we will use the append function by calling np.append(). It is used to append values to the end of a given array.

Syntax:

``````numpy.append
(
arr,
values,
axis=None
)``````

Example:

``````import numpy as np

emp_array = np.array([])
arr =([2,3,4])
res = np.append(emp_array,arr)
print(res)``````

Here is the Screenshot of following given code.

Read: Python NumPy Sum + Examples

## Python numpy append row

• In this section, we will learn about python numpy append row.
• We will use a function numpy.reshape().This method will change the shape of the numbers numpy array into the given values of rows and columns.
• In numpy append 2d, we can easily use the function that is np. reshaping. This reshapes function gives a new shape to a numpy array without changing its data.

Syntax:

``````numpy.append
(
arr,
values,
axis=None
)``````

Example:

``````import numpy as np
num = np.arange(4)

c = num.reshape(2,2)

Here is the Screenshot of the following given code.

This is an example of a Python numpy append row.

## Python NumPy append column

• In this section, we will learn about the python numpy append column.
• We will use the method np.reshape().This function will change the shape of the numpy array into the specified given number of rows and columns.
• In NumPy append 2d, we can easily use a function that is np.reshape().
• This function gives a new shape to a numpy array without changing its data.
• To append a column in a numpy array we use the method np.append().

Syntax:

``````numpy.append
(
arr,
values,
axis=None
)``````
1. array: input array
2. values: values to be added in the array.
3. axis: axis along which we want to solve the sum value.

Example:

``````import numpy as np
num = np.arange(4)

c = num.reshape(2,2)
new_column = (np.append(c,[,],axis=1))
print(new_column)``````

Here is the Screenshot of the following given code.

This is an example of Python NumPy append column.

## Python numpy append two arrays

• In this section, we will learn about the python NumPy append two arrays.
• To use this function, you have to make sure that the two numpy arrays have the same length and size.
• The axis argument specifies the index of the new axis.
• We will start by declaring a new script with the NumPy library.
• Next, we will create a new numpy array called numbers or data by calling np. arange() and passing in the integer.
• This function will declare an array with integers. Now we will use the append function by using np. append().

Syntax:

``````numpy.append
(
arr,
values,
axis=None
)``````

Example:

``````import numpy as np

a = np.array([2,3])
b = np.array([4,5])
new_arr = np.append(a,b)
print(new_arr)``````

Here is the Screenshot of following given code.

This is how to append two arrays in Python NumPy.

## Python NumPy append axis

• In this section, we will learn about the python NumPy append axis.
• We will use a function n.reshape().This method will change the shape of the numbers numpy array into the specified given number of rows and columns.
• In numpy append 2d, we can easily use a function that is np.reshape().
• This np.reshape() function gives a new shape to a numpy array without changing its data.

Syntax:

``````numpy.append
(
arr,
values,
axis=None
)``````
1. array: input array
2. values: values to be added in the array.
3. axis: axis along which we want to calculate the sum value.

Example:

``````import numpy as np
num = np.arange(4)

b = num.reshape(2,2)
num_2d = (np.append(b,[[4,5]],axis=0))
print(num_2d)``````

Here is the Screenshot of the following given code.

## Python NumPy append an element to array

• In this section, we will learn about the python numpy append an element to the array.
• The values will be concatenated at the end of the numpy array and a new numpy dimension array will be returned with new and old values.
• We will start by creating a new script with the NumPy library imported as np.
• Next, we will create a numpy array called numbers or data by calling np.arange() and passing the integer value.
• This function will declare a NumPy array with integers.

Syntax:

``````numpy.append
(
arr,
values,
axis=None
)``````

Example:

``````import numpy as np

a = np.array([2,3])
b = np.array([4,5])
new_arr = np.append(a,b)
print(new_arr)``````

Here is the Screenshot of the following given code.

This is how to append an element to an array in Python NumPy.

## Python NumPy append not working

• In this section, we will learn about the python numpy append not working.
• To use this method, you have to make sure that the two numpy arrays have the same length and the size.

Example:

``````import numpy as np

a = np.array()
print(a)
np.append(a, )
print(a)``````

Here is the Screenshot of following given code.

## Python NumPy append array to array

• In this section, we will learn about the python numpy append array to array.
• The axis parameter specifies the index of the given axis.
• We will start by declaring a new script with the NumPy library.
• Next, we will create a new numpy array called numbers by using numpy.arange() and passing in the integer value which will declare a NumPy array with integers.
• Now we will use the append function by using numpy.conctenate().

Syntax:

``````numpy.conctenate
(
arr,
values,
axis=None
)``````

Example:

``````import numpy as np

a = np.array([2,3])
b = np.array([4,5])
new_arr = np.concatenate((a,b),axis=0)
print(new_arr)``````

Here is the Screenshot of following given code.

This is an example of Python NumPy append array to array.

You may like:

In this Python Numpy tutorial, we will discuss Python NumPy append with a few examples like below:

• Python numpy append 2d array
• Python numpy append to an empty array
• Python numpy append row
• Python numpy append column
• Python numpy append two arrays
• Python numpy append axis
• Python numpy append array to array
• Python numpy append an element to the array
• Python numpy append not working