创建QR二维码

============================= Pure python QR Code generator ============================= This module uses the Python Imaging Library (PIL) to allow for the generation of QR Codes. What is a QR Code? ================== A Quick Response code is a two-dimensional pictographic code used for its fast readability and comparatively large storage capacity. The code consists of black modules arranged in a square pattern on a white background. The information encoded can be made up of any kind of data (e.g., binary, alphanumeric, or Kanji symbols) Usage ===== Use the ``make`` shortcut function:: import qrcode img = qrcode.make('Some data here') Advanced Usage -------------- For more control, use the ``QRCode`` class. For example:: import qrcode qr = qrcode.QRCode( version=1, error_correction=qrcode.constants.ERROR_CORRECT_L, box_size=10, border=4, ) qr.add_data('Some data') qr.make(fit=True) img = qr.make_image() The ``version`` parameter is an integer from 1 to 40 that controls the size of the QR Code (the smallest, version 1, is a 21x21 matrix). Set to ``None`` and use the ``fit`` parameter when making the code to determine this automatically. The ``error_correction`` parameter controls the error correction used for the QR Code. The following four constants are made available on the ``qrcode`` package: ``ERROR_CORRECT_L`` About 7% or less errors can be corrected. ``ERROR_CORRECT_M`` (default) About 15% or less errors can be corrected. ``ERROR_CORRECT_Q`` About 25% or less errors can be corrected. ``ERROR_CORRECT_H``. About 30% or less errors can be corrected. The ``box_size`` parameter controls how many pixels each "box" of the QR code is. The ``border`` parameter controls how many boxes thick the border should be (the default is 4, which is the minimum according to the specs).