python文件和文件流操作

f = open(r‘C:\Users\wangxue2\Desktop\somefile.txt‘, ‘w‘)f.write(‘01234567890123456789‘)f.seek(5) #seek(offset,[ ,whence])，把当前位置（进行读和写的位置）移动到由offset和whence定义的位置f.write(‘Hello,world! my baby。‘) #这个操作不是插入操作，而是替换操作，可使用\n换行f.close()f = open(r‘C:\Users\wangxue2\Desktop\somefile.txt‘)print(f.read())

#迭代def process(string):    print(‘Precessing: ‘, string)#用read迭代每个字符f = open(r‘C:\Users\wangxue2\Desktop\somefile.txt‘)for char in f.read():    process(char)f.close()

#用readline迭代行f = open(r‘C:\Users\wangxue2\Desktop\somefile.txt‘)for line in f.readline():    process(line)f.close()

#用fileinput对行迭代import fileinput

for line in fileinput.input(r‘C:\Users\wangxue2\Desktop\somefile.txt‘):    process(line)

#文件迭代器f = open(r‘C:\Users\wangxue2\Desktop\somefile.txt‘)for line in f:    process(line)f.close()#对文件进行迭代而不使用变量存储文件对象for line in open(r‘C:\Users\wangxue2\Desktop\somefile.txt‘):    process(line)#迭代标准输入中的所有行import sysfor line in sys.stdin:    process(line)