Reversing a List in Prolog

Your solution explained: If we reverse the empty list, we obtain the empty list. If we reverse the list [H|T] , we end up with the list obtained by reversing T and concatenating with [H] . To see that the recursive clause is correct, consider the list [a,b,c,d] . If we reverse the tail of … Read more

Get first row value of a given column

To select the ith row, use iloc: To select the ith value in the Btime column you could use: There is a difference between df_test[‘Btime’].iloc[0] (recommended) and df_test.iloc[0][‘Btime’]: DataFrames store data in column-based blocks (where each block has a single dtype). If you select by column first, a view can be returned (which is quicker than returning a copy) and the original dtype is preserved. In … Read more

How do I use ‘git reset –hard HEAD’ to revert to a previous commit? [duplicate]

First, it’s always worth noting that git reset –hard is a potentially dangerous command, since it throws away all your uncommitted changes. For safety, you should always check that the output of git status is clean (that is, empty) before using it. Initially you say the following: So I know that Git tracks changes I make to my application, … Read more