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：
