二十九 有点难

file_name = input('请输入文件名：')
print('请输入内容，单独输入“：w” 保存退出：')
f = open(file_name,'w')
text =input()
while text != ':w':
    f.write(text+'\n')
    text =input()

1：

def read_files(file_name):
    print('请输入需要比较的文件名：%s'%file_name)
    f = open(file_name,'r')
    return f

f1 = read_files('1')
f2 = read_files('222')
dif = []
i = 0
count =0
for line in f1.readlines():
    i += 1
    line2 = f2.readlines()
    if line != line2:
        count +=1
        dif.append(i)
print('共有%d处不同'%count)
for i in range(count):
    print('第%d处不同在%d行'%(i,dif[i]))

2：我坦白了 我抄的答案  好难啊 呜呜呜

def get_file_N(file_name,s_e):
    if s_e.split() ==':':
        start = 1
        end =-1
    (start,end) = s_e.split(':')
    if start == '':
        start = 1
    if end =='':
        end =-1

    if start == '1' and end == '-1':
        prompt = '的全文'
    elif start == '1':
        prompt = '从开始到%s' % end
    elif end == '-1':
        prompt = '从%s到结束' % start
    else:
        prompt = '从第%s行到第%s行' % (start, end)

    print('\n文件%s%s的内容如下：\n' % (file_name, prompt))
    start = int(start) -1
    end =int (end)
    lines = end - start
    f = open(file_name)
    for i in range(start):
        f.readline()
    if lines < 0:
        print(f.read()) #如果end =-1 读到最后的意思
    else :
        for j in range(lines):
            print(f.readline(),end='')


get_s_e = input("请输入开始/结束的行数：形式 a：b")
get_file_N('1',get_s_e)

3：再次抄答案 

def file_replace(file_name, rep_word, new_word):
    f_read = open(file_name)

    content = []
    count = 0

    for eachline in f_read:
        if rep_word in eachline:
            count = eachline.count(rep_word) #count感觉应该用这个
            eachline = eachline.replace(rep_word, new_word)
        content.append(eachline)

    decide = input('\n文件 %s 中共有%s个【%s】\n您确定要把所有的【%s】替换为【%s】吗？\n【YES/NO】：' \
                   % (file_name, count, rep_word, rep_word, new_word))

    if decide in ['YES', 'Yes', 'yes']:
        f_write = open(file_name, 'w')
        f_write.writelines(content)
        f_write.close()

    f_read.close()


file_name = input('请输入文件名：')
rep_word = input('请输入需要替换的单词或字符：')
new_word = input('请输入新的单词或字符：')
file_replace(file_name, rep_word, new_word)