Python学习笔记（十五）用Python获取本地数据

f1 = open(r'E:\Python\Data\data1.txt')  #读取data1.txt文件，使用系统默认缓冲区大小, 为了读取快点，使用缓存吧！

f = open(r'E:\Python\Data\data2.txt', 'w')

f.write('Hello World !')

f.close()

f = open(r'E:\Python\Data\data2.txt', 'r')

p1 = f.read(5)  # 先读5个字节

p2 = f.read()   # 余下的都读出来

f.close()

f = open(r'E:\Python\Data\data3.txt')

cNames = f.readlines()   #把数据从文件一行行读取，返回一个列表

print(cNames)

f.close()

#结果， readlines()读取的结果中，不去掉换行符

['GOOGLE Inc\n', 'Nicrosoft Corporation\n', 'Apple Inc.\n', 'Facebook, Inc.']

# Filename:revcopy.py

f1 = open(r'E:\Python\Data\data3.txt')   # 读

cNames = f1.readlines()

for i in range(0, len(cNames)):

    cNames[i] = str(i+1) + '.' + cNames[i]

f1.close()

f2 = open(r'E:\Python\Data\data3_out.txt', 'w')  # 写

f2.writelines(cNames)

f2.close()

s = 'Tencent Technology Company Limited'

f = open(r'E:\Python\Data\data3.txt', 'a+')

f.writelines('\n')

f.writelines(s)

f.seek(0, 0)            # 把文件指针移到文件首部

cNames = f.readlines()

print(cNames)

f.close()