Python核心编程 第九章练习

笔者刚刚开始Python的系统学习，所以在代码上还无法达到pythonic的水准，很多写法也都是按照C++的习惯来写的，希望能有前辈进行交流指导。

欢迎拍砖

9_1

#!/usr/bin/python2
# coding: utf-8

if __name__ == '__main__':
with open('example.txt') as f:
for each_line in f:
if '#' in each_line:
pos = each_line.find('#')
if pos > 0:
print each_line[: pos]
else:
continue
else:
print each_line

9_2

#!/usr/bin/python2
# coding: utf-8

import os

def FilePathCheck(F):
if os.path.isfile(F):
return F
path = os.getcwd()
curdirF = os.path.join(path, F)
if os.path.isfile(curdirF):
return curdirF
return
if __name__ == '__main__':
F = raw_input('Please input the file name: ')
file_path = FilePathCheck(F)
if file_path:
with open(file_path) as f:
N = int(raw_input('Please input the line number: '))
for i in range(N):
print f.readline(),
else:
print 'the file name is not valid!'

9_3

#!/usr/bin/python2
# coding: utf-8

import os

def FilePathCheck(F):
if os.path.isfile(F):
return F
path = os.getcwd()
curdirF = os.path.join(path, F)
if os.path.isfile(curdirF):
return curdirF
return
if __name__ == '__main__':
F = raw_input('Please input the file name: ')
file_path = FilePathCheck(F)
if file_path:
with open(file_path) as f:
lst_line = f.readlines()
print 'the number of rows are %s' %len(lst_line)
else:
print 'the file name is not valid!'

9_4

#!/usr/bin/python2
# coding: utf-8

import os

def FilePathCheck(F):
if os.path.isfile(F):
return F
path = os.getcwd()
curdirF = os.path.join(path, F)
if os.path.isfile(curdirF):
return curdirF
return
if __name__ == '__main__':
F = raw_input('Please input the file name: ')
file_path = FilePathCheck(F)
if file_path:
with open(file_path) as f:
while True:
try:
raw_input('Press any key to continue...')
for i in range(25):
line = f.readline()
if line == '':
raise EOFError
print line,
except(EOFError, KeyboardInterrupt):
break

else:
print 'the file name is not valid!'

9_5

#!/usr/bin/env python
# encoding: utf-8

from __future__ import division #to make the python do the real division
import os

def Classify(value):
if value > 90:
return 'A'
if value > 80:
return 'B'
if value > 70:
return 'C'
if value > 60:
return 'D'
else:
return 'F'

def FilePathCheck(F):
if os.path.isfile(F):
return F
path = os.getcwd()
curdirF = os.path.join(path, F)
if os.path.isfile(curdirF):
return curdirF
return
if __name__ == '__main__':
F = raw_input('Please input the file name: ')
file_path = FilePathCheck(F)
if file_path:
with open(file_path) as f:
str_mark = f.read()
lst_mark = str_mark.split()
lst_fmark = [float(i) for i in lst_mark]
lst_fmark.sort()
sum_lst = sum(lst_fmark)
avg_lst = sum_lst/len(lst_fmark)
print "the average grade is %0.2f" %avg_lst
class_lst = [Classify(i) for i in lst_fmark]
print class_lst

9_6

#!/usr/bin/python2
# coding: utf-8

import os

def FilePathCheck(F):
if os.path.isfile(F):
return F
path = os.getcwd()
curdirF = os.path.join(path, F)
if os.path.isfile(curdirF):
return curdirF
return
if __name__ == '__main__':
F1 = raw_input('Please input the file name: ')
F2 = raw_input('Please input another file name: ')
file_path1 = FilePathCheck(F1)
file_path2 = FilePathCheck(F2)
if file_path1 and file_path2:
with open(file_path1) as f1:
with open(file_path2) as f2:
line1 = f1.readlines()
line2 = f2.readlines()
for i in range(min(len(line1), len(line2))):
if line1[i] == line2[i]:
continue
else:
print 'The different line is %s' %(i+1)
break
else:
print 'All lines are the same'

9_8

参考了birdzb的答案，第一次发现原来模块可以这么用！长见识了。他的链接是：http://blog.csdn.net/birdzb/article/details/49981091。真前辈也！

#/usr/bin/python2
# coding: utf-8

if __name__ == '__main__':
module = raw_input('Please input a module name: ')
mod = __import__(module)
dir_mod = dir(mod)
print dir_mod
for i in dir_mod:
print 'name: %s' %i
print 'type: %s' %type(getattr(mod, i))
print 'value: %s' %getattr(mod, i)
print

9_9

这是birdzb的答案，他的链接是：http://blog.csdn.net/birdzb/article/details/49981091。

import os
pymodules = {}
path = r'/usr/lib/python2.7'
pyfiles = [f for f in os.listdir(path) if f.endswith('.py')]
for f in pyfiles:
module = f[:-3]
pymodules.setdefault(module, '')
pyfile = path + os.sep + f
fobj = open(pyfile)
doc = False
for line in fobj:
if line.strip().startswith('"""''"""')and line.strip().endswith('"""'):
pymodules[module] += line
fobj.close()
break
elif (line.strip().startswith('"""''"""') or line.strip().startswith('r"""')) and len(line)>3:
doc = True
pymodules[module] += line
continue
elif doc:
if line == '"""':
pymodules[module] += line
fobj.close()
doc = False
break
else:
pymodules[module] += line
else:
continue
else:
fobj.close()
hasdoc = []
nodoc = []
for module in pymodules:
if pymodules[module]:
hasdoc.append(module)
else:
nodoc.append(module)

print 'module has no doc:'
for key in nodoc:
print key
print '\n'
print 'module has doc:'
for key in hasdoc:
print 'module:', key
print 'doc:', pymodules[key]

9_10

这个题目写的规模比较大，主要原因是自己花了3个晚上的时间来学习wxPython的GUI使用（白天要在实验室弄实验室项目（与python无关），忙成狗，实在没办法写python）。总体来讲这个图形界面的模块不难入门，用起来也比Tkinter这个模块更舒服些。之所以放弃已经初步了解的Tkinter，改投wxpython，是因为wxPython使用的人多一些，无论是基础的教程还是排异解难都要方便些，为了提早出坑，所以才开始学习wxPython。想自己了解wxPython的可以访问http://wiki.wxpython.org/Getting%20Started#Getting_started_with_wxPython。

wxPython的安装，linux下可以使用 sudo apt-get install python-wxtools， windows没查过，教程也很多。

现在初步了解了几个控件的使用，但是具体的排版和编辑还是差强人意，请忽略我糟糕的审美，毕竟我的美术是体育老师教的。（这年头教体育背锅上万吨）

#!/usr/bin/env python
# coding: utf-8

import wx
import os
class BankFrame(wx.Frame):
def __init__(self, parent, title):
wx.Frame.__init__(self, parent, title=title, size=(500,100))
# 创建分页
self.nb = wx.Notebook(self)

# 创建储蓄
self.panel_depos = wx.Panel(self.nb)
sizer_depos = wx.BoxSizer(wx.VERTICAL)
self.button_dep_save = wx.Button(self.panel_depos
, label="Save")
self.button_dep_withdraw = wx.Button(self.panel_depos
, label="Withdraw")
sizer_depos.Add(self.button_dep_save, 1, wx.EXPAND)
sizer_depos.Add(self.button_dep_withdraw, 1, wx.EXPAND)
self.panel_depos.SetSizerAndFit(sizer_depos)
self.Bind(wx.EVT_BUTTON, self.OnSave, self.button_dep_save)
self.Bind(wx.EVT_BUTTON, self.OnWithdraw, self.button_dep_withdraw)

# 创建金融市场
self.panel_finan = wx.Panel(self.nb)
sizer_finan = wx.BoxSizer(wx.VERTICAL)
self.button_fin_borrow = wx.Button(self.panel_finan,
label="Borrow")
self.button_fin_loan = wx.Button(self.panel_finan,
label="Loan")
sizer_finan.Add(self.button_fin_borrow, 1, wx.EXPAND)
sizer_finan.Add(self.button_fin_loan, 1, wx.EXPAND)
self.panel_finan.SetSizerAndFit(sizer_finan)

# 将界面放到分页中
self.nb.AddPage(self.panel_depos, "Deposite")
self.nb.AddPage(self.panel_finan, "Financial Market")

def OnSave(self, event):
self.Hide()     # 隐藏主界面
self.text = "0" # 初始化数据

# 读取信息
file_name = "deposit.txt"
f = FileExist(file_name, 'r')
lst_data = f.readlines()
f.close()
self.sum_of_depos = float(lst_data[len(lst_data)-1].strip())

# 设置界面
self.frame_save = wx.Frame(None, title="Save")
quote_msg = wx.StaticText(self.frame_save, label="Your bank acount has %s yuan left"
%self.sum_of_depos)
quote_save = wx.StaticText(self.frame_save, label="How much do you want to save?")
text_save = wx.TextCtrl(self.frame_save, size = (100, 20))
button_save = wx.Button(self.frame_save, label="OK")
save_sizer = wx.BoxSizer(wx.VERTICAL)
save_sizer.Add(quote_msg, wx.EXPAND)
save_sizer.Add(quote_save, wx.EXPAND)
save_sizer.Add(text_save, wx.EXPAND)
save_sizer.Add(button_save, wx.EXPAND)
self.frame_save.SetSizerAndFit(save_sizer)
self.frame_save.Show()

# 设置响应
self.frame_save.Bind(wx.EVT_BUTTON, self.Save, button_save)
self.frame_save.Bind(wx.EVT_TEXT, self.EvtText, text_save)

def OnWithdraw(self, event):
self.Hide()
self.text = "0"

file_name = "deposit.txt"
f = FileExist(file_name, 'r')
lst_data = f.readlines()
f.close()
self.sum_of_depos = float(lst_data[len(lst_data)-1].strip())

self.frame_withdraw = wx.Frame(None, title="Withdraw")
quote_msg = wx.StaticText(self.frame_withdraw, label="Your bank acount has %s yuan left"
%self.sum_of_depos)
quote_withdraw = wx.StaticText(self.frame_withdraw, label="How much do you want to withdraw?")
text_withdraw = wx.TextCtrl(self.frame_withdraw, size = (100, 20))
button_withdraw = wx.Button(self.frame_withdraw, label="OK")
withdraw_sizer = wx.BoxSizer(wx.VERTICAL)
withdraw_sizer.Add(quote_msg, wx.EXPAND)
withdraw_sizer.Add(quote_withdraw, wx.EXPAND)
withdraw_sizer.Add(text_withdraw, wx.EXPAND)
withdraw_sizer.Add(button_withdraw, wx.EXPAND)
self.frame_withdraw.SetSizerAndFit(withdraw_sizer)
self.frame_withdraw.Show()

# 设置响应
self.frame_withdraw.Bind(wx.EVT_BUTTON, self.Withdraw, button_withdraw)
self.frame_withdraw.Bind(wx.EVT_TEXT, self.EvtText, text_withdraw)

def Save(self, event):
self.frame_save.Close(True)
self.Show()
amount = float(self.text.strip())
self.sum_of_depos += amount
f = FileExist("deposit.txt", "a")
f.write("%s\n" %self.sum_of_depos)
f.close()

def Withdraw(self, event):
self.frame_withdraw.Close(True)
self.Show()
amount = float(self.text.strip())
if self.sum_of_depos > amount:
self.sum_of_depos -= amount
f = FileExist("deposit.txt", "a")
f.write("%s\n" %self.sum_of_depos)
f.close()
else:
dlg = wx.MessageDialog(self, "Warning", "You don't have enough deposite", wx.OK)
dlg.ShowModal()
dlg.Destroy()

def EvtText(self, event):
self.text = event.GetString()

def FileExist(file_name, mode):
curdir = os.getcwd()
path = os.path.join(curdir, file_name)
if (not os.path.isfile(path)):
f = open(path, "w")
f.write("0\n")
f.close()
f = open(path, mode)
return f

app = wx.App(False)
frame = BankFrame(None, "Family Account")
frame.Show()
app.MainLoop()

9_11

这个部分也花了很久的时间，主要用于考察正则表达式的含义了。由于刚刚开始完全不懂正则是什么，所以看博客看起来很吃力，唯一让我豁然开朗也最接近于我们的使用的是https://wiki.ubuntu.org.cn/Python%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E6%93%8D%E4%BD%9C%E6%8C%87%E5%8D%97这个文章，推荐看看。

注：该答案中没有加入判断url是否正确的功能

#!/usr/bin/env python
# coding: utf-8

import wx
import os

class URLFrame(wx.Frame):
def __init__(self, parent, title):
wx.Frame.__init__(self, parent, title=title)
file_name = "9_11url.html"
self.FileCreate(file_name)

self.nb = wx.Notebook(self)
# add url panel
self.add_panel = wx.Panel(self.nb)
grid = wx.GridBagSizer(hgap=3, vgap=4)
hSizer = wx.BoxSizer(wx.VERTICAL)
# add txt blank
self.lbl_name = wx.StaticText(self.add_panel, label="name")
self.lbl_url = wx.StaticText(self.add_panel, label="url")
self.lbl_remark= wx.StaticText(self.add_panel, label="remark")
self.ctrl_name = wx.TextCtrl(self.add_panel, size = (50, 20))
self.ctrl_url = wx.TextCtrl(self.add_panel, size=(150, 20))
self.ctrl_remark = wx.TextCtrl(self.add_panel, size=(100, 20))
# grid operation
grid.Add(self.lbl_name, pos=(0,0))
grid.Add(self.lbl_url, pos=(0,1))
grid.Add(self.lbl_remark, pos=(0,2))
grid.Add(self.ctrl_name, pos=(1,0))
grid.Add(self.ctrl_url, pos=(1,1))
grid.Add(self.ctrl_remark, pos=(1,2))
grid.Add((3,2), pos=(2,0))
# sizer operation
self.button_add = wx.Button(self.add_panel, label="Add")
hSizer.Add(grid, 4, wx.ALL, 9)
hSizer.Add(self.button_add, 1, wx.CENTER)
self.add_panel.SetSizerAndFit(hSizer)
self.nb.AddPage(self.add_panel, "Add Url")

# edit url panel
self.edit_panel = wx.Panel(self.nb)
with open(self.path, "r") as f:
self.lst_urlmsg = f.read().split(r"\n")
self.len_url = len(self.lst_urlmsg)
grid_edit = wx.GridBagSizer(hgap=3, vgap=self.len_url)
hSizer_edit = wx.BoxSizer(wx.VERTICAL)
self.name_lst = []
self.url_lst = []
self.remark_lst = []
lst_msg=[]
for i, urlmsg in enumerate(self.lst_urlmsg):
if urlmsg=="":
continue
lst_msg = urlmsg.split(",")
str_name = lst_msg[0]
str_url = lst_msg[1]
str_remark = lst_msg[2]
ctrl_name = wx.TextCtrl(self.edit_panel, size=(50, 20))
ctrl_name.AppendText(str_name)
ctrl_url = wx.TextCtrl(self.edit_panel, size=(150, 20))
ctrl_url.AppendText(str_url)
ctrl_remark = wx.TextCtrl(self.edit_panel, size=(100, 20))
ctrl_remark.AppendText(str_remark)
grid_edit.Add(ctrl_name, pos=(i,0))
grid_edit.Add(ctrl_url, pos=(i,1))
grid_edit.Add(ctrl_remark, pos=(i,2))
self.name_lst.append(ctrl_name)
self.url_lst.append(ctrl_url)
self.remark_lst.append(ctrl_remark)
self.button_edit = wx.Button(self.edit_panel, label="Edit")
hSizer_edit.Add(grid_edit, 0, wx.ALL)
hSizer.Add(self.button_edit, 1, wx.CENTER);
self.edit_panel.SetSizerAndFit(hSizer_edit)
self.nb.AddPage(self.edit_panel, "Edit Url")

self.Bind(wx.EVT_BUTTON, self.Add, self.button_add)
self.Bind(wx.EVT_BUTTON, self.Edit, self.button_edit)

def Add(self, event):
str_name = self.ctrl_name.GetValue().strip()
str_url = self.ctrl_url.GetValue().strip()
str_remark = self.ctrl_remark.GetValue().strip()
with open(self.path, "a") as f:
if str_name!="" and str_url!="":
f.write(r"%s,%s,%s\n" %(str_name, str_url, str_remark))

def Edit(self, event):
num = len(self.name_lst)
with open(self.path, "w") as f:
for i in range(num):
str_name = self.name_lst[i].GetValue().strip()
str_url = self.name_lst[i].GetValue().strip()
str_remark = self.remark_lst[i].GetValue().strip()
f.write(r"%s,%s,%s\n" %(str_name, str_url, str_remark))

def FileCreate(self, file_name):
curdir = os.getcwd()
self.path = os.path.join(curdir, file_name)
if (not os.path.isfile(self.path)):
f = open(self.path, "w")
f.close()

app = wx.App(False)
frame = URLFrame(None, "URL Management System")
frame.Show()
app.MainLoop()

9_12

这段代码写起来倒是不难，可是为了定位错误原因，花了我整整一个晚上的时间。利用cPickle每次数据都没有保存起来，无论怎么读，都是空，真是折腾死了。

最后成功定位原因：在函数中，我定义了g_users这个全局变量，于是我就在各个class里面自然而然用了c++的逻辑到处使用了。但python其实此时是创建了局部的变量，所以我的传值一直不成功，才导致了这个问题。

最后得到的经验教训是：

全局变量记得加global

全局变量记得加global

全局变量记得加global

#!/usr/bin/python
# coding: utf-8

import wx
import os
import cPickle
import string

availChar = string.lowercase + string.uppercase
g_path = ''
g_users = {}

class AccountFrame(wx.Frame):
def __init__(self, parent, title):
global g_path
global g_users
wx.Frame.__init__(self, parent, title=title, size=(200, 200))
file_name = "9_12_Account.txt"
#self.FileCreate(file_name)
curdir = os.getcwd()
self.path = os.path.join(curdir, file_name)
g_path = self.path
f = open(self.path, 'r')
self.users = cPickle.load(f)
f.close()
g_users = self.users
self.btn_log = wx.Button(self, label="user loggin")
self.btn_show = wx.Button(self, label="Show all users")
self.btn_del = wx.Button(self, label="Delete user")
self.btn_quit = wx.Button(self, label="Quit")
hSizer = wx.BoxSizer(wx.VERTICAL)
hSizer.Add(self.btn_log, 1, wx.CENTER)
hSizer.Add(self.btn_show, 1, wx.CENTER)
hSizer.Add(self.btn_del, 1, wx.CENTER)
hSizer.Add(self.btn_quit, 1, wx.CENTER)
self.SetSizerAndFit(hSizer)

self.Bind(wx.EVT_BUTTON, self.Loggin, self.btn_log)
#self.Bind(wx.EVT_BUTTON, self.Show, self.btn_show)
#self.Bind(wx.EVT_BUTTON, self.Delete, self.btn_del)
self.Bind(wx.EVT_BUTTON, self.Quit, self.btn_quit)
self.Bind(wx.EVT_CLOSE, self.Quit, self)

def Loggin(self, event):
self.Hide()
LogginFrame(self)
def Quit(self, event):
global g_users
f = open(self.path, 'w')
cPickle.dump(g_users, f, 0)
f.close()
self.Destroy()

def FileCreate(self, file_name):
curdir = os.getcwd()
self.path = os.path.join(curdir, file_name)
g_path = self.path
if (not os.path.isfile(self.path)):
f = open(self.path, "wb")
f.close()
class LogginFrame(wx.Frame):
def __init__(self, parent):
wx.Frame.__init__(self, parent=None, title="Loggin")
global g_users
self.parent = parent
self.txt_name = wx.StaticText(self, label="Name:", size=(80,30))
self.txt_passwd = wx.StaticText(self, label="Password:",size=(80,30))
self.ctrl_name = wx.TextCtrl(self, size=(150,30))
self.ctrl_passwd = wx.TextCtrl(self, size=(150,30))
self.btn_ok = wx.Button(self, label="Ok")
grid_log = wx.GridBagSizer(hgap=2, vgap=4)
grid_log.Add(self.txt_name, pos=(0,0))
grid_log.Add(self.ctrl_name, pos=(0,1))
grid_log.Add(self.txt_passwd, pos=(1,0))
grid_log.Add(self.ctrl_passwd, pos=(1,1))
hSizer = wx.BoxSizer(wx.VERTICAL)
hSizer.Add(grid_log, 4, wx.ALL, 2)
hSizer.Add(self.btn_ok, 1, wx.EXPAND)
self.SetSizerAndFit(hSizer)

self.Bind(wx.EVT_BUTTON, self.Ok, self.btn_ok)
self.Bind(wx.EVT_CLOSE, self.Quit, self)
self.Show()
def Quit(self, event):
self.parent.Show()
self.Destroy()

def Ok(self, event):
global g_users
name = self.ctrl_name.GetValue()
password = self.ctrl_passwd.GetValue()
bNameOk = True
for i in name:
if i not in availChar:
bNameOk = False
break
if not bNameOk:
dlg = wx.MessageDialog(self, "Not a available name", "warning", wx.OK)
elif name in g_users.keys():
if password == g_users[name]:
dlg = wx.MessageDialog(self, "welcome back", "info", wx.OK)
else:
dlg = wx.MessageDialog(self, "password not correct", "warning", wx.OK)
else:
g_users[name] = password

dlg = wx.MessageDialog(self, name, password, wx.OK)
dlg.ShowModal()
dlg.Destroy()
self.parent.Show()
self.Destroy()

if __name__ == "__main__":
app = wx.App(False)
frame = AccountFrame(None, "Loggin System")
frame.Show()
app.MainLoop()

＃9_13

#!/usr/bin/python
# coding: utf-8

import sys
if __name__ == "__main__":
argvs = sys.argv
print "all the argvs are: ",
for i in argvs:
print i,

9_14

#!/usr/bin/python
# coding: utf-8

from __future__ import division
import sys

if __name__ == "__main__":
argv = sys.argv
math = []
for i in range(1, len(argv)):
math.append(argv[i])
str_math = ''.join(math)
b_math = True
for i in "+-*/^":
if i in str_math:
break
else:
b_math = False
if b_math:
ab = str_math.split(i)
a = float(ab[0])
b = float(ab[1])
if i is "+":
print a+b
elif i is "-":
print a-b
elif i is "*":
print a*b
elif i is "/":
print a/b
else:
print a**b

9_15

#!/usr/bin/python
# coding: utf-8

import sys
import os

if __name__ == "__main__":
argv = sys.argv
if len(argv) != 3:
print "not right parameters"
os._exit(1)
file1 = argv[1]
file2 = argv[2]
curdir = os.getcwd()
path1 = os.path.join(curdir, file1)
path2 = os.path.join(curdir, file2)
with open(path1, 'r') as f1:
with open(path2, 'w') as f2:
data = f1.read()
f2.write(data)
print "copy finished"

9_16

发现一个大神，代码写的极其漂亮，推荐大家去看看。下面的答案来自他的主页。http://www.xmanblog.net/2015/04/29/%E3%80%8Apython%E6%A0%B8%E5%BF%83%E7%BC%96%E7%A8%8B%E3%80%8B%E7%AC%AC%E4%B9%9D%E7%AB%A0%E7%BB%83%E4%B9%A0%E8%A7%A3%E6%9E%90/。

#!/usr/bin/python
# coding: utf-8

def check_text():
"""文档处理函数，对长度超过80的进行截断"""
f = open("1.txt", "r")
lines_1 = f.readlines()
f.close()
lines_2 = [] #将新生成的文档先储存在lines_2中
for line in lines_1:
if len(line)>80:
if line[80] == " ": #如果81个位置是空格，就不需要考虑单词边界问题
lines_2.append(line[:80]+"n")
lines_2.append(line[81:])
else:
local = line[:80].rfind(" ") #否则查找最靠近第80个位置的空格截断，保持单词的完整性
lines_2.append(line[:local]+"n")
lines_2.append(line[local+1:])
else:
lines_2.append(line)
f = open("1.txt", "w")
f.writelines(lines_2)
f.close()

if __name__ == "__main__":
"""主函数"""
while True: #循环检测每行的长度，直至长度全部小鱼或等于80
f = open("1.txt", "r")
lines = f.readlines()
f.close()
for line in lines:
if len(line)>80:
check_text()
break
else:
break
print "Done!"

9_17

#!/usr/bin/python
# coding: utf-8

import os
def Create():
"""Create a file"""
file_name = raw_input("Please input a file name: ")
current_dir = os.getcwd()
path = os.path.join(current_dir, file_name)
f = open(path, "w")
file_content = []
print "Please input file content, press Ctrl + d to stop: "
while True:
try:
f.write(raw_input()+"\n")
except (EOFError, KeyboardInterrupt, IndexError):
f.close()
break

def Show():
"""Show the content on the screen"""
file_name = raw_input("Please input a file name: ")
current_dir = os.getcwd()
path = os.path.join(current_dir, file_name)
f = open(path, "r")
for line in f:
print line,
f.close()

def Edit():
"""Edit a file content"""
file_name = raw_input("Please input a file name: ")
current_dir = os.getcwd()
path = os.path.join(current_dir, file_name)
with open(path, "r") as f:
lines = f.readlines()
row_number = int(raw_input("Please input the row number: "))
row_content = raw_input("Please edit content: ") + "\n"
lines[row_number-1] = row_content
with open(path, "w") as f:
for line in lines:
f.write(line)

def Menu():
CMD = {"c": Create, "s": Show, "e": Edit}
msg_help = """Please choose:
(C)reate
(S)how
(E)dit
(Q)uit"""
print msg_help
msg = "Your choice: "
while True:
try:
choice = raw_input(msg).strip().lower()[0]
except (EOFError, KeyboardInterrupt, IndexError):
choice = 'q'
if choice not in "cseq":
msg = "Wrong choice, input again: "
continue
else:
break
if choice is not "q":
CMD[choice]()

if __name__ == "__main__":
Menu()

9_18

#!/usr/bin/python
# coding:utf-8

import os

def count(path, ord_of_str):
sum_of_str = 0
str_to_find = chr(ord_of_str)
with open(path) as f:
for line in f:
sum_of_str += line.count(str_to_find)
return sum_of_str

if __name__ == "__main__":
cur_dir = os.getcwd()
file_name = raw_input("Please input a file name: ")
path = os.path.join(cur_dir, file_name)
ord_of_str = int(raw_input("Please input a number: "))
sum_of_str = count(path, ord_of_str)
print "the string used %s times" %sum_of_str

9_19

#!/usr/bin/python
# coding:utf-8

import os

def count(path, ord_of_str):
sum_of_str = 0
str_to_find = chr(ord_of_str)
with open(path) as f:
for line in f:
sum_of_str += line.count(str_to_find)
return sum_of_str

if __name__ == "__main__":
cur_dir = os.getcwd()
file_name = raw_input("Please input a file name: ")
path = os.path.join(cur_dir, file_name)
ord_of_str = int(raw_input("Please input a number: "))
sum_of_str = count(path, ord_of_str)
print "the string used %s times" %sum_of_str

9_20

这个程序很简单，我就不多做介绍了，随便一搜就能找到gzip的资料。

#!/usr/bin/python
# coding:utf-8

import gzip
import os

def gz(file_name):
"""gzip a file at the current work directory"""
curdir = os.getcwd()
path = os.path.join(curdir, file_name)
g_file_name = file_name + ".gz"
g_file = gzip.GzipFile(g_file_name, "wb")
print g_file_name
g_file.write(open(path).read())
g_file.close()

def ungz(g_file_name):
"""ungzip a file"""
g_file_name_tuple = os.path.splitext(g_file_name)
file_name = g_file_name_tuple[0]
g_file = gzip.GzipFile(g_file_name)
open(file_name, "w+").write(g_file.read())
g_file.close()

if __name__ == "__main__":
CMDS = {"g": gz, "u" : ungz}
msg_help = """(G)zip
(U)ngzip
(Q)uit

Please choose: """
while True:
try:
choice = raw_input(msg_help).strip().lower()[0]
except (EOFError, KeyboardInterrupt, IndexError):
choice = 'q'
if choice not in "guq":
msg_help = "Wrong choice, please input again: "
else:
break
if choice != 'q':
file_name = raw_input("Input a file name: ")
CMDS[choice](file_name)

9_21

#!/usr/bin/python
# coding: utf-8

import zipfile
import os

def CreateZipFile(z_file_name):
"""Create a zip file
z_file_name: zipfile's name"""
curdir = os.getcwd()
path = os.path.join(curdir, z_file_name)
file_name = raw_input("Input a file name: ")
file_path = os.path.join(curdir,file_name)
z_file = zipfile.ZipFile(path, "w")
z_file.write(file_path, file_name, zipfile.ZIP_DEFLATED)
z_file.close()

def ExtraZipFile(z_file_name):
"""Extract a zip file"""
curdir = os.getcwd()
path = os.path.join(curdir, z_file_name)
z_file = zipfile.ZipFile(path)
for file in z_file.namelist():
z_file.extract(file, curdir)
z_file.close()

if __name__ == "__main__":
msg_help = """(C)reate a zip file
(E)xtract a zip file
(Q)uit

Please choose: """
CMDs = {"c" : CreateZipFile, "e" : ExtraZipFile}
while True:
try:
choice = raw_input(msg_help).strip().lower()[0]
except (EOFError, KeyboardInterrupt, IndexError):
choice = "q"
if choice not in "ceq":
msg_help = "Wrong input, try again: "
continue
else:
break
if choice is not "q":
file_name = raw_input("Input a zip file name: ")
CMDs[choice](file_name)