README

Welcome to the vignette for PytrendsLongitudinalR, a package for collecting and analyzing Google Trends data over time. This vignette will guide you through the setup process and show you how to use the package’s main functionalities.

This is a package for downloading cross-section and time-series Google Trends and converting them to longitudinal data. Although Google Trends provides cross-section and time-series search data, longitudinal Google Trends data are not readily available. There exist several practical issues that make it difficult for researchers to generate longitudinal Google Trends data themselves. First, Google Trends provides normalized counts from zero to 100. As a result, combining different regions’ time-series Google Trends data does not create desired longitudinal data. For the same reason, combining cross-sectional Google Trends data over time does not create desired longitudinal data. Second, Google Trends has restrictions on data formats and timeline. For instance, if you want to collect daily data for 2 years, you cannot do so. Google Trends automatically provides weekly data if your request timeline is more than 269 days. Similarly, Google Trends automatically provides monthly data if your request timeline is more than 269 weeks even though you want to collect weekly data. This package resolves the aforementioned issues and allows researchers to generate longitudinal Google Trends.

Installation

To use the PytrendsLongitudinalR package, you need Python version 3.7 or higher installed on your system. Follow the steps below to check if Python is installed and, if not, how to install it.

Check if Python is installed: Open a terminal (on Linux/Mac) or Command Prompt (on Windows) and run the following command:

If you see a version number (e.g., Python 3.8.5), you’re ready to proceed. If Python is not installed or the version is below 3.7, you’ll need to install or update it.

Install Python (Optional - since installing the package in Step 2 will automatically handle Python installations): MacOS and Windows: Download the latest version of Python from the official Python website: https://www.python.org/downloads/.

Linux: Most Linux distributions already include Python, but if you need to install it or update to a newer version, run:


sudo apt-get update
sudo apt-get install python3

Once Python is installed, you can proceed with installing the PytrendsLongitudinalR package. This package interacts with Python to retrieve Google Trends data, so it requires some additional Python packages (pandas, requests, pytrends) to work correctly. The process is automated using the install_pytrendslongitudinalr() function.

The function automatically creates an isolated Python virtual environment named pytrends-in-r-new to keep the Python packages separate from your system Python and installs the required Python packages in this virtual environment.

Run the following code to install PytrendsLongitudinalR and automatically create an isolated virtual environment named “pytrends-in-r-new”:


install.packages('PytrendsLongitudinalR')

library(PytrendsLongitudinalR)

# This will create a virtual environment and install the necessary Python packages in the virtual environment
install_pytrendslongitudinalr(envname = "pytrends-in-r-new")

What this does: It checks if the virtual environment pytrends-in-r-new already exists. If it doesn’t exist, it creates it and installs the required Python packages (pandas, requests, pytrends). If you ever need to reinstall the environment, the function can also remove and recreate the environment.

Troubleshooting Python Installation Issues: Windows users: If you run into errors related to Python not being found, ensure Python is added to your PATH during installation. You can verify this by running python –version in the command line. MacOS users: If Python is not found, ensure that you are using the command python3 and that Python 3 is installed (since macOS may also have Python 2 by default).

Manual Installation (optional - not recommended for this package): If you prefer to manually install the Python packages outside of R, you can run the following command in your terminal (if you have pip or pip3 installed):


pip3 install pytrends pandas requests

After running this command, the PytrendsLongitudinalR package should work as expected with your existing Python setup.

Usage

library(PytrendsLongitudinalR)
install_pytrendslongitudinalr(envname = "pytrends-in-r-new")

# Initialize parameters for data collection
params <- initialize_request_trends(
  keyword = "Coronavirus disease 2019",
  topic = "/g/11j2cc_qll",
  folder_name = file.path(tempdir(), "test_folder"),
  start_date = "2024-05-01",
  end_date = "2024-05-03",
  data_format = "daily"
)

# Collect cross-section data
cross_section(params, geo = "US", resolution = "REGION") # REGION as a resolution is a sub-region of US in this example, and it indicates US states.

# Collect reference time-series data
time_series(params, reference_geo_code = "US-CA") # The selected reference is California and its Google Trends Geo is 'US-CA'.

# Given the short time period in this example, no concatenation is needed.
concat_time_series(params, reference_geo_code = "US", zero_replace = 0.1) # Error occurs because given period is less than 269 days, concatenation is unnecessary. You can move to convert_cross_section() without any problems.

# Use the reference time-series data to re-scale the cross-sectional data. 
convert_cross_section(params, reference_geo_code = "US-CA")

Warning

First, the cross-sectional and reference time-series data must be created. The concat_time_series() function uses the reference time-series data files to concatenate multiple sets of time series. Finally, the convert_time_series() function uses the concatenated reference time series to re-scale the cross-sectional data.

The user may encounter a 429 Too Many Requests error when using cross_section() and time_series() to collect Google Trends data. This error indicates that the user has exceeded the rate limits set by the Google Trends API. Here are a few strategies to mitigate the impact of this error: