How is the function of python verification code timestamp realized?

If the verification code is to be displayed successfully, there must be a verification code generator, so write a verification code generator. I created a new py file check_coed.py file in the app, which is the verification code generator. The code is as follows

Random import

Import image from PIL, image drawing, image font, image filter.

_ letter _ cases = "abcdefghjkmnpqrstuwxy" # lowercase letters, remove I, L, O, Z that may interfere.

_ upper _ cases = _ letter _ cases.upper () # capital letters

_ numbers =“”。 Join (map (str, range (3, 10)) # number

init_chars =“”。 Join((_letter_cases, _ capital, _numbers))

def create _ validate _ code(size =( 120，30)，

chars=init_chars，

img_type="GIF "，

mode="RGB "，

bg_color=(255，255，255)，

fg_color=(0，0，255)，

font_size= 18，

font_type="Monaco.ttf "，

Length =4,

draw_lines=True，

n_line=( 1，2)，

draw_points=True，

point_chance=2):

"""

@todo: generate verification code picture

@param size: the size and format (width and height) of the picture. The default value is (120,30).

@param chars: allowed character set, format string.

@param img_type: save the format of the picture. The default is GIF, and the options are GIF, JPEG, TIFF and PNG.

@param mode: picture mode, which is RGB by default.

@param bg_color: background color, which is white by default.

@param fg_color: foreground color, character color of verification code, and blue #0000FF by default.

@param font_size: font size of verification code.

@param font_type: the font of the verification code; the default is AE _ alaarabiya.ttf.

@param length: the number of characters of the verification code.

@param draw_lines: Do you want to draw interference lines?

@param n_lines: number range of interference lines, format tuple, which is (1, 2) by default, and only valid when draw_lines is True.

@param draw_points: whether to draw interference points.

@param point_chance: probability of interference point, size range [0, 100]

@return: [0]: PIL mirror instance

@return: [1]: the string in the verification code picture.

"""

Width, Height = Size # Width and Height

# Create graphics

Img = Image.new (mode, size, background color)

Draw = ImageDraw。 Draw (img) # Create a brush

def get_chars():

"""Generates a string of a given length and returns a list format" ""

Returns random.sample (character, length)

Define create_lines ():

"""Draw interference lines" ""

Line _ num = random. Randint (* n _ line) # Number of interference lines

For I (line number) in range:

# Starting point

begin = (random.randint(0，size[0])，random.randint(0，size[ 1]))

# Endpoint

end = (random.randint(0，size[0])，random.randint(0，size[ 1]))

draw.line([begin，end]，fill=(0，0，0))

Define creation points ():

"""Draw interference points" ""

Chance = min (100, max (0, int (point _ chance)) # Size is limited to [0, 100].

For w (width) in the range:

For h (height) in the range:

tmp = random.randint(0， 100)

If tmp> 100-opportunity:

draw.point((w，h)，fill=(0，0，0))

def create_strs():

"""Draw verification code characters" ""

c_chars = get_chars()

Strs =' %s'% '。 Join(c_chars) # Each character is separated by a space.

# font = image font . truetype(font _ type，font_size)

font = ImageFont.load_default()。 script

font_width，font_height = font.getsize(strs)

draw . text((width-font _ width)/3，(height - font_height) / 3)，

strs，font=font，fill=fg_color)

Return "". Join (c_chars)

If you draw a line:

Create _ Line ()

If you draw a _ point:

Create Points ()

strs = create_strs()

# Graphic distortion parameter

params =[ 1-float(random . randint( 1，2)) / 100，

0，0，0， 1-float(random.randint( 1， 10)) / 100，float(random.randint( 1，2)) / 500，0.00 1，float(random . randint( 1，2)) / 500 ]

Img = img.transform (size, image.perspective, params) # Create a warp.

Img = img.filter (imagefilter.edge _ enhance _ more) # filter, with enhanced boundary (larger threshold).