【python-练习】python核心编程第三章练习一

练习3-11与练习3-12的答案：
#!/usr/bin/env python
import os
def write():
    filename = raw_input("Enter the file name:")
    try:
        fobj = open(filename,'r')
    except IOError:
        print "*** file is not exists can write***"
    else:
        fobj.close()
    all = []
    print "\nEnter lines ('.' by itself to quit).\n"
    while True:
        entry = raw_input('> ')
        if entry == '.':
            break
        else:
            all.append(entry)
    f = open(filename,'w')
    f.writelines(['%s%s' % (x,'\n') for x in all])
    f.close()
    print "DONE!"


def read():
    filename = raw_input("Enter the file name:")
    while True:
        if os.path.exists(filename) != True:
            print "Error:'%s' is not exists!" % filename
        else:
            fobj = open(filename,'r')
            for i in fobj:
                o = i.strip()
                print o
            fobj.close()
            break

while True:
    make = raw_input("What is you want?(Enter write read or quit):")
    if make == 'write':
        write()
    elif make == 'read':
        read()
    elif make == 'quit':
        break
    else:
        pass