How can i insert values from a list into a pandas data frame column?

i have this dataframe:

i want to insert new x values to the x column

new_x = [0, 0.03, 0.07, 0.1, 0.13, 0.17, 0.2]

so that the dataframe becomes

so basically for every new_x value that doesn’t exist in column x, the y value is NaN

is it possible to do it in pandas? thank you

>Solution :

You can use Numpy’s searchsorted.

After you create a new_y array that is the same length as the new_x array. You use searchsorted to identify where in the new_y array you need to drop the old y values.

new_y = np.full(len(new_x), np.nan, np.float64)
new_y[np.searchsorted(new_x, df.x)] = df.y

pd.DataFrame({'x': new_x, 'y': new_y})

      x    y
0  0.00  3.0
1  0.03  NaN
2  0.07  4.0
3  0.10  6.0
4  0.13  5.0
5  0.17  NaN
6  0.20  NaN