How to Fetch and Save Stock Price

Historical stock prices are available on a significant number of websites to download but wouldn't it be easier to use a script to fetch these prices and save it to our local machine?

In this article, we will learn how to fetch the historic stock prices of a company using Python. Let's first import the required dependencies to perform the actions.

# Get the dates
import datetime
# Create files in the operating system
import os

# Convert data frames to file formats
import pandas as pd
# Fetch the stock prices
import pandas_datareader as web
# Find relative dates of the past or of the future
from dateutil.relativedelta import relativedelta

Now, create a StockPrice class with a helper function fetch to fetch the stock price and save function to save the stock prices to the local folder.

class StockPrice:
    """
    Provide functionality to fetch the historical stock prices and save it to a path
    """

    def __init__(self):
        """
        Entry point to the class
        """
        self.data_source = 'yahoo'
        self.path = 'data/'

    def fetch(self, ticker_symbol, start, end):
        """
        Fetch the data from pre-defined source between the start and end time
        :param ticker_symbol:
        :param start: start time in yyyy-mm-dd
        :param end: end time in yyyy-mm-dd
        :return: data frame with the historical stock prices
        """
        return web.DataReader(ticker_symbol, self.data_source, start, end)

    def save(self, df, file_name):
        """
        Save the data frame to a csv file in the local folderz
        :param df: data frame with historical stock prices
        :param file_name: name of the csv files
        """
        # Create the path
        created = self.create_path()
        print('New Path created', created)

        # Create and write to a csv file
        self.write_csv(df, file_name)
        # Create and write to an excel file
        self.write_excel(df, file_name)

    def create_path(self):
        """
        Create a path in the system
        :return: True if the path was created because it doesn't exist and false otherwise
        """
        if not os.path.exists(self.path):
            # Path doesn't exists, create the path
            os.makedirs(self.path)
            return True
        return False

    def write_excel(self, df, file_name):
        """
        Create a file of format xlsx
        :param df: data frame with historical stock prices
        :param file_name: name of the csv files
        """
        writer = pd.ExcelWriter(self.path + file_name + ".xlsx", datetime_format='dd/mm/yyy')
        df.to_excel(writer)
        writer.close()

    def write_csv(self, df, file_name):
        """
        Create a file of format csv
        :param df: data frame with historical stock prices
        :param file_name: name of the csv files
        """
        df.to_csv(self.path + file_name + ".csv")

To fetch the stock price, we use DataReader function which is part of pandas_datareader library. It takes a source, ticker symbol and start time, end time in yyyy-mm-dd format. We can pass today's date as the end time using datetime.date.today and n years old date as the start time by subtracting relativedelta from the today's date.

We are using the source as yahoo in this example, instead of that, we can also use robinhood, quandl or any other available source.

DataReader returns a pandas data frame object and this can be saved in the csv format using to_csv or in the xlsx format using to_excel functions. One thing to note is that if the path passed to these functions doesn't exist, they will throw FileNotFoundError. So it is a good practice to check whether the path exists or not before creating the files.

# Assign a ticker symbol
ts = 'BAJFINANCE.NS'

# Create an instance of the class
stockPrice = StockPrice()
# Fetch the stock price
df_ts = stockPrice.fetch(
    ts,
    datetime.date.today() - relativedelta(years=10),
    datetime.date.today()
)
# Print the first 5 rows
print(df_ts.head())
# Print the last 5 rows
print(df_ts.tail())
# Save the stock price
stockPrice.save(df_ts, ts.replace(".", "_"))

Running the above script creates two files; BAJFINANCE_NS.csv and BAJFINANCE_NS.xlsx in the data folder. Most of the time, we work with either of the file formats, so we can choose to use either write_csv or write_excel function.

Popular posts from this blog

How to Read Metadata from AndriodManifest File

Metadata tags are key-value pairs and one of the decent ways to access the API keys from the libraries. They are added to the AndroidManifest.xml under the application tag and are available through the PackageManager . If you have worked with third-party libraries or even with App shortcuts, Downloadable Fonts, Firebase MLKit, you may have come across metadata tags. In the article, let’s add the metadata tags to the app module’s Manifest file and read the metadata key-values and the key-resource from a library module both in kotlin and java. Add meta-data: Add metadata to the app module's AndroidManifest.xml file under the application tag. You can add as many metadata elements as you want and you can also add metadata under the activity, service, broadcast receiver, content provider tags. <meta-data android:name= "com.gsrikar.library.LIBRARY_ACCESS_KEY" android:value= "masndfiu4er9funwikesd" /> <meta-data and
Read more

Mr Phone - Find The Next Best Phone You Want To Buy

Image
Want to buy a phone and not sure which phone to choose? Mr Phone is a phone search application and is here to help you find the best phone. The application was built by acidandrage and is available in the Google Play Store with In-app purchases. Search for your device and detailed specs gets loaded along with the image. You can tap the image for more pics or save the phone specs to view later. You can compare specs of any two phones or choose to use the Best Fit option. The Best Fit option of the app will show you the list of best-matched phones based on the preferred specs you've selected. Sections like New Releases and Popular shows the newly released phones and the phones that became most popular recently. While Stories section gives you to the Top Stories about smartphones, apps, and the Events section notifies you about the launch events of the smartphones. Great Day Readers! To give us more insights into the application development, Ashish Hooda, Head of
Read more

Add Spacing to Recycler View Linear Layout Manager Using Item Decoration

Image
In this article we will learn about, item decoration in Android and how we can use it to add even spacing between the child items. A RecyclerView without spacing will look like the image below but in most cases, we want to add spacing between the items. [You can see there are no margins between the views and only elevation] A more traditional option is adding margins in the list item xml file. If we take this route, we will soon end up with uneven spacing issues with vertical margins. [There are even left, right, top, bottom margins for all the rows except the last item in the first image and in the subsequent image, the top margin for the first item is half of the other items] The best way is to add the ItemDecoration to the RecyclerView as it affects the individual items and you can have more control over them. Kotlin: /** * Add vertical, horizontal spacing to the recycler view */ class DefaultItemDecorator(private val horizontalSpacing: Int,
Read more

Add Options Menu to Activity and Fragment

Image
Options Menu contains a set of primary menu items that are accessible to the user. In this article, we will take a look at how to implement the options menu in an Android Activity or a Fragment. Right click on the res directory in Android Studio and select Android Resource File option. It opens the Resource File creation modal where we need to enter the file name and select Resource Type as Menu. Clicking on OK button creates main_menu.xml under menu directory. Now add the following items to the XML file. <menu xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <item android:id="@+id/search" android:icon="@drawable/ic_search_white" android:orderInCategory="100" android:title="@string/action_title_search" app:actionViewClass="androidx.appcompat.widget.SearchView" app:showAsAction="ifRoo
Read more

Create Assets Folder, Add Files and Read Data From It

Image
Sometimes, we need to read the data stored in the files during runtime and want to make sure the data is not tampered by the Android build system. In this article, we will take a look at how to create the assets folder using Android Studio and read the stored data from it. First, Right-click on the module name or the package name. This opens an option window where we need to select the Assets Folder option by hovering over New and then on the Folder option. Now, we will see a window where we change the folder location and the source set. Change the values if necessary otherwise keep the defaults and click Finish. It may trigger a Gradle Sync. Irrespective of the sync, the Assets folder is created and is visible in the module. Now, Right-click on the Assets folder and click on the File option by hovering over the New option. Enter the name of the file name and click Enter to create the file. The file with the name user_details.json is created under the assets folder. Add some JSON
Read more