Filter-join df1 for observations also in df2

str_detect: Detect patterns in texts, using fixed("") for "(, ), *, ', $, +" fct_collapse: Collapse factor levels into manually defined groups Trim (remove whitespace from) column names and set to lowercase Set values out of range to upper detection limit in new column Find obs not present in both dfs - missing obs. Anti_join Filter-join df1 for observations also in df2 Filter dataframe1 by column in dataframe2 inner_join, arrange and add suffixes Combine two data tables with same column names + Replace NAs with 0s Separate or join variables over/from 2 columns - tidyr::separate() / unite() Replace NA with previous row value - fill() Replace NA's with column mean