使用 Python 生成二维条形码 QR Codes

前几天，我估摸着做一个能生成QR Code小程序，并能用wxPython在屏幕上显示出来。当然，我想用纯Python实现，观望了一会后，我找到了三个候选：

• github 上的 python-qrcode
• sourceforge上的 pyqrcode
• Goolge code 上的 pyqrnative

我尝试了python-qrcode以及pyqrnative，因为它们能够运行在Windows/Mac/Linux。也不需要依赖额外的其他库除了Python图像库。pyqrcode项目需要其他一些先决条件，并且不能在Windows上运行，所以我不想与之纠缠了。我最后使用了一些以前写过的一个Photo Viewer程序的代码，然后稍微地修改了一下，就成了QRCode的查看器了。

开始

正如我上面提到的，你只需要Python图像库，GUI部分我们将使用wxPython。python-qrcode相比pyqrnative生成图片更快，并包含了你见过的大多数QR码类型。

生成 QR Codes

当你准备好所有需要的以后，你可以运行以下代码，看看Python做了些啥：

import os
import wx
 
try:
    import qrcode
except ImportError:
    qrcode = None
 
try:
    import PyQRNative
except ImportError:
    PyQRNative = None
 
########################################################################
class QRPanel(wx.Panel):
    """"""
 
    #----------------------------------------------------------------------
    def __init__(self, parent):
        """Constructor"""
        wx.Panel.__init__(self, parent=parent)
        self.photo_max_size = 240
        sp = wx.StandardPaths.Get()
        self.defaultLocation = sp.GetDocumentsDir()
 
        img = wx.EmptyImage(240,240)
        self.imageCtrl = wx.StaticBitmap(self, wx.ID_ANY,
                                         wx.BitmapFromImage(img))
 
        qrDataLbl = wx.StaticText(self, label="Text to turn into QR Code:")
        self.qrDataTxt = wx.TextCtrl(self, value="http://www.mousevspython.com", size=(200,-1))
        instructions = "Name QR image file"
        instructLbl = wx.StaticText(self, label=instructions)
        self.qrPhotoTxt = wx.TextCtrl(self, size=(200,-1))
        browseBtn = wx.Button(self, label='Change Save Location')
        browseBtn.Bind(wx.EVT_BUTTON, self.onBrowse)
        defLbl = "Default save location: " + self.defaultLocation
        self.defaultLocationLbl = wx.StaticText(self, label=defLbl)
 
        qrcodeBtn = wx.Button(self, label="Create QR with qrcode")
        qrcodeBtn.Bind(wx.EVT_BUTTON, self.onUseQrcode)
        pyQRNativeBtn = wx.Button(self, label="Create QR with PyQRNative")
        pyQRNativeBtn.Bind(wx.EVT_BUTTON, self.onUsePyQR)
 
        # Create sizer
        self.mainSizer = wx.BoxSizer(wx.VERTICAL)
        qrDataSizer = wx.BoxSizer(wx.HORIZONTAL)
        locationSizer = wx.BoxSizer(wx.HORIZONTAL)
        qrBtnSizer = wx.BoxSizer(wx.VERTICAL)
 
        qrDataSizer.Add(qrDataLbl, 0, wx.ALL, 5)
        qrDataSizer.Add(self.qrDataTxt, 1, wx.ALL|wx.EXPAND, 5)
        self.mainSizer.Add(wx.StaticLine(self, wx.ID_ANY),
                           0, wx.ALL|wx.EXPAND, 5)
        self.mainSizer.Add(qrDataSizer, 0, wx.EXPAND)
        self.mainSizer.Add(self.imageCtrl, 0, wx.ALL, 5)
        locationSizer.Add(instructLbl, 0, wx.ALL, 5)
        locationSizer.Add(self.qrPhotoTxt, 0, wx.ALL, 5)
        locationSizer.Add(browseBtn, 0, wx.ALL, 5)
        self.mainSizer.Add(locationSizer, 0, wx.ALL, 5)
        self.mainSizer.Add(self.defaultLocationLbl, 0, wx.ALL, 5)
 
        qrBtnSizer.Add(qrcodeBtn, 0, wx.ALL, 5)
        qrBtnSizer.Add(pyQRNativeBtn, 0, wx.ALL, 5)
        self.mainSizer.Add(qrBtnSizer, 0, wx.ALL|wx.CENTER, 10)
 
        self.SetSizer(self.mainSizer)
        self.Layout()
 
    #----------------------------------------------------------------------
    def onBrowse(self, event):
        """"""
        dlg = wx.DirDialog(self, "Choose a directory:",
                           style=wx.DD_DEFAULT_STYLE)
        if dlg.ShowModal() == wx.ID_OK:
            path = dlg.GetPath()
            self.defaultLocation = path
            self.defaultLocationLbl.SetLabel("Save location: %s" % path)
        dlg.Destroy()
 
    #----------------------------------------------------------------------
    def onUseQrcode(self, event):
        """

https://github.com/lincolnloop/python-qrcode

        """
        qr = qrcode.QRCode(version=1, box_size=10, border=4)
        qr.add_data(self.qrDataTxt.GetValue())
        qr.make(fit=True)
        x = qr.make_image()
 
        qr_file = os.path.join(self.defaultLocation, self.qrPhotoTxt.GetValue() + ".jpg")
        img_file = open(qr_file, 'wb')
        x.save(img_file, 'JPEG')
        img_file.close()
        self.showQRCode(qr_file)
 
    #----------------------------------------------------------------------
    def onUsePyQR(self, event):
        """

http://code.google.com/p/pyqrnative/

        """
        qr = PyQRNative.QRCode(20, PyQRNative.QRErrorCorrectLevel.L)
        qr.addData(self.qrDataTxt.GetValue())
        qr.make()
        im = qr.makeImage()
 
        qr_file = os.path.join(self.defaultLocation, self.qrPhotoTxt.GetValue() + ".jpg")
        img_file = open(qr_file, 'wb')
        im.save(img_file, 'JPEG')
        img_file.close()
        self.showQRCode(qr_file)
 
    #----------------------------------------------------------------------
    def showQRCode(self, filepath):
        """"""
        img = wx.Image(filepath, wx.BITMAP_TYPE_ANY)
        # scale the image, preserving the aspect ratio
        W = img.GetWidth()
        H = img.GetHeight()
        if W > H:
            NewW = self.photo_max_size
            NewH = self.photo_max_size * H / W
        else:
            NewH = self.photo_max_size
            NewW = self.photo_max_size * W / H
        img = img.Scale(NewW,NewH)
 
        self.imageCtrl.SetBitmap(wx.BitmapFromImage(img))
        self.Refresh()
 
 
########################################################################
class QRFrame(wx.Frame):
    """"""
 
    #----------------------------------------------------------------------
    def __init__(self):
        """Constructor"""
        wx.Frame.__init__(self, None, title="QR Code Viewer", size=(550,500))
        panel = QRPanel(self)
 
if __name__ == "__main__":
    app = wx.App(False)
    frame = QRFrame()
    frame.Show()
    app.MainLoop()

python-qrcode生成效果图：

PyQRNative生成效果图：