A secondary carbocation is one in which there. are two carbons attached to the carbon bearing the positive charge. Likewise, a tertiary. carbocation is one in which there are three carbons attached to the carbon bearing the. positive charge. Methyl carbocations. No CâC+ bonds.
Numeric keypad. A numeric keypad, number pad, numpad, or ten key, is the palm-sized, 17-key section of a standard computer keyboard, usually on the far right.It provides calculator-style efficiency for entering numbers.he arrangement of digits on numeric keypads with the 7-8-9 keys two rows above the 1-2-3 keys is derived from calculators and cash registers. It is notably different from the layout of telephone Touch-Tone keypads which have the 1-2-3 keys on top and 7-8-9 keys on the third row.
import numpy as np dat = np.array([[1, 2, 3], [4, 5, np.nan], [np.nan, 6, np.nan], [np.nan, np.nan, np.nan]]) print(dat) print(dat.mean(1)) # [ 2. nan nan nan] With NaNs removed, my expected output would be: array([ 2., 4.5, 6., nan])