[python]《Python编程快速上手:让繁琐工作自动化》学习笔记2

[python]《Python编程快速上手:让繁琐工作自动化》学习笔记2

1. 读写文件笔记（第8章）(代码下载)

1.1 文件与文件路径
通过import os调用os模块操作目录，常用函数如下：

1.2 文件读写

在Python 中，读写文件有3 个步骤：

1. 调用open()函数，返回一个File 对象。
2. 调用File 对象的read()或write()方法。
3. 调用File 对象的close()方法，关闭该文件

# 将'w'作为第二个参数传递给open(),以写模式打开该文件
# 写模式会清空源文件
baconFile = open(&#', 'w')
baconFile.write('Hello world!n')
baconFile.close()# 将'a'作为第二个参数传递给open()，以添加模式打开该文件
# 添加模式将在已有文件的末尾添加文本
baconFile = open(&#', 'a')
baconFile.write('Bacon is not a vegetable.')
baconFile.close()# 读文件
baconFile = open(&#')
# read将文件的内容看成是单个大字符串
content = ad()
# readlines从该文件取得一个字符串的列表。列表中的每个字符串就是文本中的每一行
# content = adlines()
baconFile.close()
print(content)

Hello world!
Bacon is not a vegetable.

2. 项目练习

2.1 生成随机的测验试卷文件

# -*- coding: utf-8 -*-
import random# 测验数据
# The quiz data. Keys are states and values are their capitals.
capitals = {'Alabama': 'Montgomery', 'Alaska': 'Juneau', 'Arizona': 'Phoenix',
'Arkansas': 'Little Rock', 'California': 'Sacramento', 'Colorado': 'Denver',
'Connecticut': 'Hartford', 'Delaware': 'Dover', 'Florida': 'Tallahassee',
'Georgia': 'Atlanta', 'Hawaii': 'Honolulu', 'Idaho': 'Boise', 'Illinois':
'Springfield', 'Indiana': 'Indianapolis', 'Iowa': 'Des Moines', 'Kansas':
'Topeka', 'Kentucky': 'Frankfort', 'Louisiana': 'Baton Rouge', 'Maine':
'Augusta', 'Maryland': 'Annapolis', 'Massachusetts': 'Boston', 'Michigan':
'Lansing', 'Minnesota': 'Saint Paul', 'Mississippi': 'Jackson', 'Missouri':
'Jefferson City', 'Montana': 'Helena', 'Nebraska': 'Lincoln', 'Nevada':
'Carson City', 'New Hampshire': 'Concord', 'New Jersey': 'Trenton', 'New Mexico': 'Santa Fe', 'New York': 'Albany', 'North Carolina': 'Raleigh',
'North Dakota': 'Bismarck', 'Ohio': 'Columbus', 'Oklahoma': 'Oklahoma City',
'Oregon': 'Salem', 'Pennsylvania': 'Harrisburg', 'Rhode Island': 'Providence',
'South Carolina': 'Columbia', 'South Dakota': 'Pierre', 'Tennessee':
'Nashville', 'Texas': 'Austin', 'Utah': 'Salt Lake City', 'Vermont':
'Montpelier', 'Virginia': 'Richmond', 'Washington': 'Olympia', 
'West Virginia': 'Charleston', 'Wisconsin': 'Madison', 'Wyoming': 'Cheyenne'}# 生成试卷
# 试卷份数    
n_quiz=2
for quizNum in range(n_quiz):# Create the quiz and answer key files.# 试卷quizFile = open('' % (quizNum + 1), 'w')# 答案answerKeyFile = open('capitalsquiz_' % (quizNum + 1), 'w')# Write out the header for the quiz.# 头文件quizFile.write('Name:nnDate:nnPeriod:nn')quizFile.write((' ' * 20) + 'State Capitals Quiz (Form %s)' % (quizNum + 1))quizFile.write('nn')# Shuffle the order of the states.states = list(capitals.keys())# 创建了美国州名的随机列表random.shuffle(states)    # 创建答案    # Loop through all 50 states, making a question for each.for questionNum in range(50):# Get right and wrong answers.# 正确答案correctAnswer = capitals[states[questionNum]]# 错误答案wrongAnswers = list(capitals.values())# 删除正确的答案del wrongAnswers[wrongAnswers.index(correctAnswer)]# 随机取出三个答案wrongAnswers = random.sample(wrongAnswers, 3)answerOptions = wrongAnswers + [correctAnswer]random.shuffle(answerOptions)    # 将内容写入测验试卷和答案文件# Write the question and the answer options to the quiz file.quizFile.write('%s. What is the capital of %s?n' % (questionNum + 1,states[questionNum]))for i in range(4):quizFile.write(' %s. %sn' % ('ABCD'[i], answerOptions[i]))quizFile.write('n')# Write the answer key to a file.   answerKeyFile.write('%s. %sn' % (questionNum + 1, 'ABCD'[answerOptions.index(correctAnswer)]))quizFile.close()answerKeyFile.close()    

2.2 疯狂填词

创建一个疯狂填词（Mad Libs）程序，它将读入文本文件，并让用户在该文本文件中出现ADJECTIVE、NOUN、ADVERB 或VERB 等单词的地方，加上他们自己的文本。

import re# text:
'''
The ADJECTIVE panda walked to the NOUN and then VERB. A nearby NOUN was unaffected by these events
'''
# 输入文件
input_file = open('./')
input_text = ad()
input_file.close()# 输出文本
output_text = input_text# 输入文本寻找关键词
keywords = repile('adjective|noun|verb', re.IGNORECASE)
mo = keywords.findall(input_text)# 一个一个词进行替换
for word in mo:if word[0].lower() == 'a':replacewords = input('Enter an {}:n'.format(word))else:replacewords = input('Enter a {}:n'.format(word))regex = repile(word)# 每一次替换一个词output_text = regex.sub(replacewords, output_text, 1)# 写入新文件
output_file = open('', 'w')
output_file.write(output_text)
output_file.close()
print(output_text)

Enter an ADJECTIVE:
silly
Enter a NOUN:
chandelier
Enter a VERB:
screamed
Enter a NOUN:
pickup truck
The silly panda walked to the chandelier and then screamed. A nearby pickup truck was unaffected by these events.

2.3 正则表达式查找

编写一个程序，打开文件夹中所有的.txt 文件，查找匹配用户提供的正则表达式的所有行。结果应该打印到屏幕上。

import os
import repath = "./"# 判断路径目录是否存在
folder = ists(path)
if folder == False:print("文件目录不存在！")#返回指定目录下所有的文件名和文件夹名列表
file_Name = os.listdir(path)#创建正则表达式
keywords = repile(r'ADJECTIVE')# 找出txt文件
for i in range(len(file_Name)):#判断是否为txt文件if os.path.isfile(os.path.join(path, file_Name[i])) and file_Name[i].split('.')[-1] == 'txt':# 打开文件file = open(os.path.join(path, file_Name[i]))file_texts = adlines()for texts in file_texts:#找出匹配正则表达式的内容text_put = keywords.search(texts)#输出结果if text_put != None:#打印当前行print('{}'.format(texts))

The ADJECTIVE panda walked to the NOUN and then VERB. A nearby NOUN was unaffected by these events.