calculated-columns

问题 I am trying to create a new column based on both columns. Say I want to create a new column z, and it should be the value of y when it is not missing and be the value of x when y is indeed missing. So in this case, I expect z to be [1, 8, 10, 8] . x y 0 1 NaN 1 2 8 2 4 10 3 8 NaN 回答1: The new column 'z' get its values from column 'y' using df['z'] = df['y'] . This brings over the missing values so fill them in using fillna using column 'x' . Chain these two actions: >>> df['z'] = df['y']

问题 I am trying to create a new column based on both columns. Say I want to create a new column z, and it should be the value of y when it is not missing and be the value of x when y is indeed missing. So in this case, I expect z to be [1, 8, 10, 8] . x y 0 1 NaN 1 2 8 2 4 10 3 8 NaN 回答1: The new column 'z' get its values from column 'y' using df['z'] = df['y'] . This brings over the missing values so fill them in using fillna using column 'x' . Chain these two actions: >>> df['z'] = df['y']

来源： https://stackoverflow.com/questions/50751659/multiply-several-sets-of-columns-in-the-same-data-table

来源： https://stackoverflow.com/questions/50751659/multiply-several-sets-of-columns-in-the-same-data-table

来源： https://stackoverflow.com/questions/51863479/recursive-cte-in-amazon-redshift

来源： https://stackoverflow.com/questions/25207771/sql-server-how-to-merge-two-columns-into-one-column

问题 I have a DataFrame ave_data that contains the following: ave_data Time F7 F8 F9 00:00:00 43.005593 -56.509746 25.271271 01:00:00 55.114918 -59.173852 31.849262 02:00:00 63.990762 -64.699492 52.426017 I want to add another column to this dataframe, containing the average of the values under column F7, F8 and F9 for each row. The ave_data DataFrame might change size as my code reads from different Excel files later, so the method needs to be generic (i.e add the column containing the average

问题 I have a bunch of calculated DAX columns that I want to show as a visual. If I use a normal bar chart I get the following image, Barchart 1, where because I do not have any fields in the axis field. The titles of each of the calculated columns are what I want the x-axis to be similar to how it is in the funnel chart below. The funnel chart only requires the value field to be filled in and it creates the following image which is kind of what I want but it needs to be vertical similar to the

问题 I'm very new to SQL and T-SQL, so please forgive any mistakes in terminology or if the answer is obvious - I don't even know where to start googling for the solution to this problem. I only have SELECT permission on a T-SQL server. I have a query that pulls a bunch of information based on an event with a Start Date (DATETIME) and End Date (DATETIME). I want to have a calculated column in my query result that indicates whether the person was just involved in back-to-back events. So, something

问题 1. Code Description alias how it is intended to work User enters a path to a directory in PowerShell. Code checks if any folder within the declared directory contains no data at all. If so, the path of any empty folder will be shown on the prompt to the user and eventually removed from the system. 2. The Issue alias what I am struggling with The code I just wrote doesn't count the depth of a folder hierarchy as I would expect (the column in the output table is blank). Besides that, the