Python类型提示,输出类型取决于输入类型

时间:2018-05-16 09:24:17

标签: python type-hinting

考虑以下功能

import cv2
import numpy as np

## Definitions

def get_circle(img, minR, maxR, p1, p2):
    if len(img.shape)==3:
        img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

    circles = cv2.HoughCircles(img, cv2.HOUGH_GRADIENT,1,20, param1=p1,param2=p2,minRadius=minR,maxRadius=maxR)
    circles = np.uint16(np.around(circles))

    #return the first circle
    return circles[0][0]

def print_img(img,x,y,w,h):
    if w!=0 and h!=0:
        cv2.imshow('detected circles',img[x:x+w,y:y+h])
        cv2.imwrite('app-1/1.jpg',img[x:x+w,y:y+h])
    else:
        cv2.imshow('detected circles',img)
        cv2.imwrite('app-1/1.jpg',img)
    cv2.waitKey(0)

    cv2.destroyAllWindows()

def reject_out(img, xc, yc, r):
    row = len(img)
    col = len(img[0])

    for x in range(0,row):
        for y in range(0, col):
            res = (x-xc)*(x-xc) + (y-yc)*(y-yc)
            if res > r*r :
                img[x][y] = 0

def reject_in(img, xc, yc, r):
    xs = xc-r
    ys = yc-r

    for x in range(xs,xs+2*r):
        for y in range(ys, ys+2*r):
            res = (x-xc)*(x-xc) + (y-yc)*(y-yc)
            if res < r*r :
                img[x][y] = 0

def extract_iris(img):
    cimg    = cv2.cvtColor(img, cv2.COLOR_GRAY2BGR)
    cord    = get_circle(cimg, 35, 0, 50, 40)
    # draw the outer circle
    cv2.circle(cimg,(cord[0],cord[1]),cord[2],(0,255,0),2)
    # draw the center of the circle
    cv2.circle(cimg,(cord[0],cord[1]),2,(0,0,255),3)


    h = 2*cord[2]
    w = 2*cord[2]
    x = cord[1]-cord[2]
    y = cord[0]-cord[2]
    nimg = img[x:x+w,y:y+h]

    reject_out(nimg, h/2, w/2, h/2)
    print_img(cimg,0,0,0,0)

    nimg = cv2.cvtColor(nimg, cv2.COLOR_GRAY2BGR)
    cord    = get_circle(nimg, 0, cord[2]-1, 50, 30)
    print (nimg[0:w][cord[0]])
    # draw the outer circle
    cv2.circle(nimg,(cord[0],cord[1]),cord[2],(0,255,0),2)
    # draw the center of the circle
    cv2.circle(nimg,(cord[0],cord[1]),2,(0,0,255),3)
    reject_in(nimg, cord[1], cord[0], cord[2])
    print_img(nimg,0,0,0,0)
    print (nimg[0:w][cord[0]])



img = cv2.imread('test6.jpg',0)
img = cv2.medianBlur(img,5)
extract_iris(img)

我如何提示它返回

import typing
def make_list(el : typing.Any):
    return [el, el]

1 个答案:

答案 0 :(得分:1)

这就是TypeVar的用途:

from typing import TypeVar, List

T = TypeVar('T')

def make_list(el: T) -> List[T]:
    return [el, el]
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