Update row python

Using Python replace method , we can update or change the value of any string within a data frame. We need not provide the index or label values to it. In this example, we have updated the value of the rows 0, 1, 3 and 6 with respect to the first column i. We can even provide the function with slicing of rows to change the values of multiple rows consequently using iloc function.

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Asked 7 years, 8 months ago. Active 1 year, 6 months ago. Viewed k times. I have a pandas data frame that looks like this its a pretty big one date exer exp ifor mat American M Now, how do I update this as I iterate. Tried a few things none of them worked. I don't see the values updated in the dataframe. Wilfred Hughes I think you want df.

Whether your code can be vectorized will depend on those things. In general, avoid iterrows. In your case, you should definitely avoid it since each row will be an object dtype Series. You would be better off creating a boolean mask for your condition, update all those rows and then set the rest to the other value — EdChum. Please do not use iterrows. It is a blatant enabler of the worst anti-pattern in the history of pandas.

Add a comment. Active Oldest Votes. You can assign values in the loop using df. TQA 3 3 silver badges 12 12 bronze badges. See pandas. You should never modify something you are iterating over" — Davor Josipovic.

I'm not sure if we read it exactly the same. If you look in my pseudo code I do the modification on the dataframe, not on the value from the iterator. Thank you for the clarification. Viewed 39 times. Here is my sample dataset with two columns. Any help would be appreciated. Daniel Walker 4, 3 3 gold badges 14 14 silver badges 35 35 bronze badges. Add a comment. Active Oldest Votes.

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