misc.py 文件源码

def text_png(text, scale=3):
        """Returns an open png image file with text written

        Only letters, numbers, -, >, and < are allowed. New lines are
        indicated by /
        """
        text = text.split('/')
        text_out = ['']
        for t in text:
            text_line = ['1', '1', '1', '1', '1']
            for letter in t:
                for i in range(5):
                    text_line[i] += LETTERS[letter.upper()][i] + '1'
            text_out += text_line
            text_out += ['']
        text_len = max([len(t) for t in text_out])
        text_out = [line + (text_len-len(line))*'1' for line in text_out]
        img = []
        for line in text_out:
            im_line = ''
            for n in line:
                im_line += scale*n
            img += scale*[im_line]
        png_file = NamedTemporaryFile('wb+', suffix='.png')
        png_writer = png.Writer(len(img[0]), len(img), greyscale=True, bitdepth=1)
        png_writer.write(png_file, img)
        png_file.seek(0)
        return png_file