【Python教程】csv实时一条一条插入且表头不重复问题教程

所需工具：

Python

聪明的大脑

勤劳的双手

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介绍

csv实时一条条插入且表头不重复
连续写入txt
csv写入时指定表头

教程如下

csv实时一条条插入且表头不重复

1、主要就是在最开始插入的时候判断下表头或者表格是否有数据

2、用csv reader（然后主要写是a追加模式，读是r模式）

 	import csv
 	with open("111.csv","a",encoding='utf-8',newline="") as f:
 	 
 	         k = csv.writer(f, dialect="excel")
 	         with open("111.csv", "r", encoding='utf-8', newline="") as f:
 	             reader = csv.reader(f)
 	             if not [row for row in reader]:
 	                 k.writerow(["标题", "链接", "喜欢"])
 	                 k.writerow(list)
 	             else:
 	                 k.writerow(list)

 	all_datas = [[1,2],[2,3],[1,2],[4,5]]
 	for list1 in all_datas:
 	     with open(r"ablchange1.csv", 'a+', encoding='utf-8-sig', newline="") as f:
 	 
 	         k = csv.writer(f, dialect="excel")
 	         with open("ablchange1.csv", "r", encoding='utf-8-sig', newline="") as f:
 	             reader = csv.reader(f)
 	             if not [row for row in reader]:
 	                 k.writerow(["a","b"])
 	 
 	                 k.writerow(list1)
 	             else:
 	                 k.writerow(list1)

连续写入txt

 	with open("111.txt","a") as f:
 	     for i in range(100000):
 	     f.write(str(i)+"\n")
 	     if i==9000:
 	         break

csv写入时指定表头

 	import csv
 	with open('names.csv', 'w') as csvfile:
 	     fieldnames = ['first_name', 'last_name']
 	     writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
 	     writer.writeheader()
 	     writer.writerow({'first_name': 'Baked', 'last_name': 'Beans'})
 	     writer.writerow({'first_name': 'Lovely', 'last_name': 'Spam'})
 	     writer.writerow({'first_name': 'Wonderful', 'last_name': 'Spam'})

练习

 	     with open('specific.csv', 'a', newline="") as csvfile:
 	     fieldnames = ['ebayno', "pov", "mpn", "ipn", "opn"]
 	     writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
 	     writer.writeheader()

 	     file = open("aces_less.csv","w" , newline="")
 	     writer = csv.DictWriter(file, fieldnames=["asin","state"])
 	     writer.writeheader()
 	     for i in range(len(qs)):
 	     print(qs[i])
 	     state = getDataById(qs[i])
 	     print("状态 = " + state + "\n")
 	     writer.writerow({"asin":qs[i], "state": state})