Pretty print for sklearn confusion matrix

print_cm.py

from sklearn.metrics import confusion_matrix

def print_cm(cm, labels, hide_zeroes=False, hide_diagonal=False, hide_threshold=None):
    """pretty print for confusion matrixes"""
    columnwidth = max([len(x) for x in labels]+[5]) # 5 is value length
    empty_cell = " " * columnwidth
    # Print header
    print "    " + empty_cell,
    for label in labels: 
        print "%{0}s".format(columnwidth) % label,
    print
    # Print rows
    for i, label1 in enumerate(labels):
        print "    %{0}s".format(columnwidth) % label1,
        for j in range(len(labels)): 
            cell = "%{0}.1f".format(columnwidth) % cm[i, j]
            if hide_zeroes:
                cell = cell if float(cm[i, j]) != 0 else empty_cell
            if hide_diagonal:
                cell = cell if i != j else empty_cell
            if hide_threshold:
                cell = cell if cm[i, j] > hide_threshold else empty_cell
            print cell,
        print

# first generate with specified labels
labels = [ ... ]
cm = confusion_matrix(ypred, y, labels)

# then print it in a pretty way
print_cm(cm, labels)