Numpy arrays are used for data manipulation.

**You can read the csv file into a record array in numpy using the np.genfromtxt() method.**

This tutorial teaches you how to read a CSV file into a record array in numpy.

**If you’re in Hurry**

Use the following code to read CSV file into a record array in NumPy.

```
import numpy as np
csv_arr = np.
````genfromtxt`('User_details.csv', delimiter=",",`dtype =None`, `encoding=None`)
csv_arr

- The data will default be read as a
`float`

dtype. Use`dtype=None`

to determine datatypes based on the content available in the file. - Use
`encoding=None`

to use the system’s default encoding. Otherwise, there will be a warning message.

**If You Want to Understand Details, Read on…**

The sample CSV file contains only data and doesn’t have headers. Let us convert the CSV data into a NumPy array.

Table of Contents

## Using NumPy GenFromTxt

The genfromtxt() method loads the data from the CSV file.

It provides options to **handle missing values**, and you can also specify how to handle errors on invalid data.

- The data will default be read as a
`float`

dtype. Use`dtype=None`

to determine datatypes based on the content available in the file. - Use
`encoding=None`

to use the system’s default encoding. If this optional parameter is not specified,`VisibleDeprecationWarning: Reading Unicode strings without specifying the encoding argument is deprecated`

will occur.

Use this method when you want to handle missing values in a special way.

**Code**

```
import numpy as np
csv_arr = np.
````genfromtxt`('User_details.csv', delimiter=",", `dtype =None`, `encoding=None`)
`csv_arr`

**Output**

```
array([(1, 'Shivam', 'Pandey', 'India', 1),
(2, 'Kumar', 'Ram', 'India', 1),
(3, 'Felix', 'John', 'Germany', 2)],
dtype=[('f0', '<i8'), ('f1', '<U6'), ('f2', '<U6'), ('f3', '<U7'), ('f4', '<i8')])
```

## Using NumPy LoadTxt

The loadtxt() method reads data from the text file.

You **cannot** handle missing values in the `loadTxt()`

method. Hence, all the rows in the file **must have the same number** of columns.

- The data will default be read as a
`float`

dtype. You cannot pass`dtype=None`

to automatically infer datatypes as in the file. You need to**specify the appropriate converter**function to convert the data. - Alternatively, you can read only a few columns that contain numerical data using the
`usecols`

parameter.

Use this method when your data doesn’t contain any missing values.

**Code**

The following code demonstrates how to read the first column of the CSV file into a NumPy array.

```
import numpy as np
csv_arr = np.loadtxt('User_details.csv',
````usecols = (0)`, delimiter=",")
csv_arr

**Output**

` array([1., 2., 3.])`

## Using Pandas Read_CSV

Pandas read_csv() is an alternate method to read the CSV file into a NumPy array.

It provides a dataframe, and you can use the `to_numpy()`

to convert the pandas dataframe into a NumPy array.

**Advantages**

`read_csv()`

works with the commas inside quotes.- No need to worry about the datatypes. It will automatically infer the data types based on the data.
- It is fast and has only less CPU usage.

**Code**

The following code demonstrates how to read a CSV file as a dataframe and convert it into a NumPy array.

```
import pandas as pd
df = pd.read_csv('User_details.csv', header=None)
csv_arr =
````df.values`
csv_arr

**Output**

```
array([[1, 'Shivam', 'Pandey', 'India', 1],
[2, 'Kumar', 'Ram', 'India', 1],
[3, 'Felix', 'John', 'Germany', 2]], dtype=object)
```

## Converting Specific Column from CSV to Numpy Array

To convert specific columns from CSV into a NumPy array, you can pass the `usecols`

parameter and specify the list of column indexes.

**Code**

```
import numpy as np
csv_arr = np.genfromtxt('User_details.csv', delimiter=",",
````usecols = (0)`, dtype =None, `encoding=None`)
csv_arr

**Output**

` array([1, 2, 3])`