I am using sklearn.metrics.confusion_matrix(y_actual, y_predict) to extract tn, fp, fn, tp and most of the time it works perfectly.
from sklearn.metrics import confusion_matrix
y_actual, y_predict = [1,1,1,1], [0,0,0,0]
tn, fp, fn, tp = confusion_matrix(y_actual, y_predict).ravel()
>>> [0 0 4 0] # ok
y_actual, y_predict = [1,1,1,1],[0,1,0,1]
tn, fp, fn, tp = confusion_matrix(y_actual, y_predict).ravel()
>>> [0 0 2 2] # ok
However, in some cases the confusion_matrix() doesn't always return those info and I would get ValueError as shown below.
from sklearn.metrics import confusion_matrix
y_actual, y_predict = [0,0,0,0],[0,0,0,0]
tn, fp, fn, tp = confusion_matrix(y_actual, y_predict).ravel()
>>> [4] # ValueError: not enough values to unpack (expected 4, got 1)
y_actual, y_predict = [1,1,1,1],[1,1,1,1]
tn, fp, fn, tp = confusion_matrix(y_actual, y_predict).ravel()
>>> [4] # ValueError: not enough values to unpack (expected 4, got 1)
My temporary solution is to write my own function to extract those info. Is there any way I can force the confusion_matrix() to always return the tn, fp, fn, tp output?
Thanks