How to Convert the =@RDP.Data Excel Function into Code Using the LSEG Data Library for Python

Financial analysts and developers frequently start their data‑driven workflows in Microsoft Excel using the RDP.Data function from the LSEG Workspace Excel Add‑In. As automation needs grow, many eventually need to migrate these formulas into Python for large‑scale processing, backtesting, analytics pipelines, or enterprise deployment.

This article walks you through how to translate an Excel =@RDP.Data formula into equivalent Python code using the LSEG Data Library for Python—the modern, supported interface for accessing LSEG financial data. 

Understanding What =@RDP.Data Does in Excel

The RDP.Data worksheet function connects your Excel workbook to the LSEG Workspace application, enabling retrieval of:

• Real time market data
• Reference data
• Fundamental data
• Historical data

The syntax generally looks like:

The arguments of RDP.Data are:

Note: Some parameters are used solely for formatting data in Excel, so they are not supported in the LSEG Data Library for Python.

For Example:

Use the list of instruments and fields in the Instruments and Fields arguments.

Use the Excel cell range in the Instruments and Fields arguments. 

Specify the values of the SDate ad EDate parameters in the Cell References arguments.

Specify the values for the SDate and EDate parameters in the Cell References arguments, and use the Excel cell reference ($L1) for the EDate parameter.

Generate the list of RICs using the RDP.Search function, and pass that list to the Instruments argument.

The Python Equivalent: ld.get_data()

In Python, the =@RDP.Data Excel function corresponds to the get_data() function in the LSEG Data Library for Python. The library can connect to an active LSEG Workspace Desktop session to retrieve data from the same endpoint used by the =@RDP.Data Excel function.

As part of the Access Layer, get_data() provides a unified interface for retrieving pricing snapshots, Fundamental data, and Reference data using one function call. 

It accepts the following parameters:

For Example:

Specify string values for both the universe and fields parameters. The delimiter may be either a comma or a semicolon

Provide lists of strings for the universe and fields parameters.

Mapping Excel Formula Components to Python Arguments

The mapping process is simple and consists of three steps.

1. Mapping Instruments

The first parameter (Instruments) of the =@RDP.Data Excel function specifies the instruments. Its value may be one of the following:

• A string containing a list of instruments separated by commas or semicolons
• A range of Excel cells that contains a list of instruments
• Another Workspace Excel function that returns a list of instruments, such as RDP.Search or RDP.Data

This Instruments parameter maps to the first argument, universe, in the ld.get_data method. The universe parameter accepts either a Python string or a list. Therefore, if the first argument (Instruments) of the =@RDP.Data function is a string, you can pass that same string directly to the universe parameter in ld.get_data. Alternatively, you can split the string into individual items, place them in a list of Python strings, and pass that list to the universe parameter.

A list of Python strings is simply a Python list ([]) in which each element is a string enclosed in quotes, for example:

However, if the first parameter (Instruments) of the =@RDP.Data function is an Excel cell range or another Workspace function, you must extract the list of instruments from those cells or from the function’s returned value, and then assign that data to the universe parameter as either a single string or a list of Python strings.

Sample Mappings

2. Mapping Fields

The second parameter (Fields) of the =@RDP.Data Excel function specifies the fields. Its value may be one of the following:

• A string containing a list of fields separated by commas or semicolons
• A range of Excel cells that contains a list of fields

This Fields parameter maps to the second argument, fields, in the ld.get_data method. The fields parameter accepts either a Python string or a list. Therefore, if the second argument (Fields) of the =@RDP.Data function is a string, you can pass that same string directly to the fields parameter in ld.get_data. Alternatively, you can split the string into individual items, place them in a list of Python strings, and pass that list to the fields parameter.

A list of Python strings is simply a Python list ([]) in which each element is a string enclosed in quotes, for example:

However, if the second parameter (Fields) of the =@RDP.Data function is an Excel cell range, you must extract the list of instruments from those cells, and then assign that data to the fields parameter as either a single string or a list of Python strings.

Sample Mappings

3. Mapping Parameters

The third parameter (Parameters) of the =@RDP.Data Excel function specifies the request parameters. Each item contains a parameter name and its corresponding value, separated by an equals sign, and multiple parameters are separated by commas. Its value may be one of the following:

• A string containing a list of request parameters
• An Excel cell that contains request parameters

This Parameters parameter maps to the third argument, parameters, in the ld.get_data method which expects a Python dictionary. Therefore, the value passed to this argument must be converted into a Python dictionary. 

A Python dictionary is a collection of key–value pairs enclosed in curly braces, such as {key: value}. In this context, each key represents a request parameter name, and each value represents that parameter’s value. Items are separated by commas. For example:

However, if the third parameter (Parameters) of the =@RDP.Data function is an Excel cell, users must first extract the value from that cell and then convert it into a Python dictionary.

The CH and RH Parameters

The CH and RH parameters are used solely for formatting data in Excel, so they are not required by the ld.get_data method. However, they may include companion fields, such as CH=Fd,date or RH=IN,calcdate. When such companion fields (e.g. date and calcdate) are present, they can be added to the fields parameter in the ld.get_data method.

Cell References

Request parameter values can be provided using the #<n> cell‑reference format (e.g., #1, #2). These values correspond to arguments from the fifth and subsequent arguments of the =@RDP.Data method. Users must extract the values from those arguments and then convert it into a Python dictionary.

Sample Mappings

Conversion Examples

The following are some Workspace Excel formulas and their equivalent Python code.

1. Inline values

Output:

2. A companion date field in the RH parameter

Output:

3. Cell References 

Output:

4. AVAIL function

Output:

5. GRWAVG function

Output:

6. Screener

Output:

Summay Cheat Sheet

The table below summarizes how to convert the values of the RDP.Data arguments into their equivalent Python parameters.