实验4

with open('data1_1.txt', 'r', encoding = 'utf-8') as f:

    data=f.readlines()

n = 0

for line in data:

    if line.strip('\n') == '':

        continue

    n+=1

print(f'共{n}行')

　　

 

with open('data1_1.txt', 'r', encoding = 'utf-8') as f:

    n = 0

    for line in f:

         if line.strip('\n') == '':

            continue

         n += 1

print(f'共{n}行')



 

 

 

 

with open('data1_2.txt', 'r', encoding = 'utf-8') as f:

    n = 0

    for line in f:

        if line.isspace():

            continue

        n += 1

print(f'共{n}行')

 

 

with open('data2.txt', 'r', encoding = 'utf-8') as f:

    data = f.read().split('\n')

unique_line = []

for line in data:

    if data.count(line) == 1:

        unique_line.append(line)

print(f'共{ len(unique_line) }独特行')

for i in unique_line:

    print(i)

 

 

 

ls = [ ['城市', '大致人口'],

   ['南京', '850万'],

   ['纽约', '2300万'],

   ['东京', '3800万'],

   ['巴黎', '1000万'] ]

with open('data3.csv', 'w', encoding = 'utf-8') as f:

  for line in ls:

    data = ','.join(line) + '\n'

    f.write(data)

# 从data3.csv中读出数据，把逗号替换成\t, 分行打印输出到屏幕上

with open('data3.csv', 'r', encoding = 'utf-8') as f:

  data = f.read()

print(data.replace(',', '\t'), end = '')

 

 

 

>>> import datetime

>>> t = datetime.datetime.now()

>>> t.strftime('%Y%m%d')

'20210509'

>>> type( t.strftime('%Y%m%d') )

<class 'str'>

 

with open('data6_1.txt', 'r', encoding = 'utf-8') as f:

    x = []

    data = f.readlines()

    for i in data:

        x.append(i.strip().split())

f = lambda x:x[2]

x.sort(key=f,reverse=True)

 

with open('data6_2.txt','w',encoding='utf-8') as fn:

    for j in x:

        data1 = ' ' .join(j)

        data2 = ' '.join(j) + '\n'

        print(data1)

        fn.write(data2)

 

 

q = []

with open('data7.txt', 'r') as f:

    data = f.readlines()

    x = input('输入随机抽点人数：')

    import random

    i = 0

    while i<int(x):

        y = random.choice(data)

        i = i+1

        q.append(y)

        print(y.strip())

 

with open('lucky.txt','w') as fn:

    for j in q:

        k = ''.join(j)

        fn.write(k)