python之从 CSV 文件中获取值列表

我得到了一个包含订单列表的 csv 文件，如下所示:

CUSTOMER_CODE,CUSTOMER_NAME,NAME,PRODUCT 
1044, C1, Name1, Arduino, 
1044, C1, Name1, ESP8266, 
1048, C2, Name1, Arduino Uno, 
1042, C3, Name1, ESP32, 
1049, C4, Name1, Arduino Mega, 
1042, C3, Name1, Nexus 4, 

现在我只想提取客户代码列表 [1042, 1044 ,1048 ,1049]

不是

[1042, 1044 ,1044,1044,1044,1044,1044,1044,1048,1048,1048,1048,1048,1048,1048,1049 等]

#!/usr/bin/python 
import MySQLdb, csv 
CUSTOMER_CODES = [] 
 
with open('Customers.csv','r') as csvfile: 
    reader = csv.DictReader(csvfile) 
 
    for row in reader: 
        if len(CUSTOMER_CODES) == 0: 
            #adding 1st value 
            CUSTOMER_CODES.append(int(row['CUSTOMER_CODE'])) 
        for i in range(0,len(CUSTOMER_CODES)): 
            #check each value of table 
            print CUSTOMER_CODES 
            if CUSTOMER_CODES[i] == int(row['CUSTOMER_CODE']): 
                print "Code is already here "+ str(row['CUSTOMER_CODE']) 
            else: 
                CUSTOMER_CODES.append(int(row['CUSTOMER_CODE'])) 

而不是像这样的输出:

[1044, 1045, 1047....] 

我有这个:

[1044, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1045, 1047, 1047, 1047, 1047, 1047, 1047, 1047, 1047, 1047, 

请您参考如下方法:

只需使用 set 而不是 list:

#!/usr/bin/python 
import MySQLdb, csv 
CUSTOMER_CODES = set() 
 
with open('Customers.csv','r') as csvfile: 
    reader = csv.DictReader(csvfile) 
 
    for row in reader: 
        CUSTOMER_CODES.add(int(row['CUSTOMER_CODE'])) 

或者使用集合理解(假设 Python 2.6+):

#!/usr/bin/python 
import MySQLdb, csv 
 
with open('Customers.csv','r') as csvfile: 
    reader = csv.DictReader(csvfile) 
    CUSTOMER_CODES = {int(row['CUSTOMER_CODE']) for row in reader} 

如果您想要排序列表，请添加 CUSTOMER_CODES = sorted(CUSTOMER_CODES)。