query: How do I combine two data-frames based on two columns?
positive_passages.docid: 15825
positive_passages.text: How to join (merge) data frames (inner, outer, left, right)
negative_passages.docid: 46441
negative_passages.text: Combine column from multiple rows into single row
negative_passages.docid: 15764
negative_passages.text: Joining two files
negative_passages.docid: 89041
negative_passages.text: Identify records in data frame A not contained in data frame B
negative_passages.docid: 3455
negative_passages.text: unique combinations of values in selected columns in pandas data frame and count
negative_passages.docid: 108943
negative_passages.text: Combining the second elements of a set of ordered pairs based on their first element
negative_passages.docid: 100133
negative_passages.text: Sum up rows from different data files
negative_passages.docid: 36003
negative_passages.text: Summarizing multiple columns with data.table
negative_passages.docid: 158497
negative_passages.text: reshape dataframe based on a string split in one column in R
negative_passages.docid: 154797
negative_passages.text: Oracle Combine several columns into one
negative_passages.docid: 58928
negative_passages.text: Excel, want to read a column and sum up the values that match in another column
negative_passages.docid: 8325
negative_passages.text: Excel SUMIFS based on two criteria
negative_passages.docid: 14066
negative_passages.text: Pivoting of data using two columns
negative_passages.docid: 1386
negative_passages.text: Order data frame by two columns in R
negative_passages.docid: 33391
negative_passages.text: Select rows in a dataframe in r based on values in one row
negative_passages.docid: 4905
negative_passages.text: Merging two files, one column at a time
negative_passages.docid: 146677
negative_passages.text: Create several new derived variables from existing variables in data.frame