How to combine a list of data frames into one data frame by row in R?

If you have a list of data frames, you can stack them by rows using:

# Suppose 'df_list' is a list of data frames
combined_df <- do.call(rbind, df_list)

do.call() calls the rbind() function on each element of df_list. Make sure all data frames in the list have the same column names and compatible data types.

Using dplyr

If you prefer tidyverse syntax:

library(dplyr)

combined_df <- bind_rows(df_list)

bind_rows() automatically matches column names across data frames and fills unmatched columns with NA.

Using data.table

For efficient row-binding (especially with large data), try data.table:

library(data.table)

# Convert list of data frames to data.table objects if needed
# df_list <- lapply(df_list, as.data.table)

combined_dt <- rbindlist(df_list)

rbindlist() in data.table is optimized for performance.

Pro Tips

• Ensure all data frames have identical column names and structures.
• Use argument fill = TRUE in rbindlist() if columns differ across data frames (NA fills missing columns).
• Validate each data frame’s data types to avoid unintended coercion.

Next Steps

To sharpen your broader coding skills and handle intricate data manipulation tasks, consider:

• Grokking the Coding Interview: Patterns for Coding Questions, perfect for mastering common coding scenarios.
• Grokking Data Structures & Algorithms for Coding Interviews, ideal for building robust algorithmic foundations.

For large-scale system architecture, explore Grokking System Design Fundamentals. You can also get personalized feedback from ex-FAANG engineers via Coding Mock Interviews. Finally, check out the DesignGurus.io YouTube channel for additional tutorials.