Pyhton学习（一）

读取txt或csv数据，按行读取，对每行数据根据','进行分隔，将每行数据以","为间隔分成一个列表

line = re.split(',', line)

　　对数组内元素出现的次数进行统计

 

from collections import Counter        
        list_len_array = np.array(list_len) #列表转数组
        print('总共有'+str(rows)+'行数据')
        print('Counter(list_len_array)\n', Counter(list_len_array))  # 调用Counter函数 
               
        #输出结果
        Counter(list_len_array)
     Counter({10: 63821263, 1: 872203, 2: 338684, 19: 28272, 18:             11049, 3: 895, 11: 58, 9: 25, 8: 18, 17: 16, 20: 3, 7: 2, 21: 1, 27: 1})
        

字符串保存到txt或者csv文件中总有双引号的解决办法：

不用writerow改用writer

import csv
oldf = open('temp.csv','r',newline='')
newf = open('temp2.csv','w',newline='')
for line in oldf:
    line = line.strip('\n')
    newf.write(line)
oldf.close()
newf.close()

python返回列表元素的唯一值列表;

    print(list_uid)
    list_uid_uniq = list(set(list_uid))