CSV¶
Comma-Separated Values 逗号分隔值,也称为字符分隔值
- 读
import csv
# 普通方式
with open("test.csv", "r") as csv_file:
csv_reader = csv.reader(csv_file)
headers = next(csv_reader) # 使用next()函数将迭代器先迭代一次,跳过表头
for row in csv_reader:
print(row[0], row[1])
# 字典方式(推荐)
with open("test.csv", "r") as csv_file:
csv_reader = csv.DictReader(csv_file)
# print(csv_reader.fieldnames) # 输出表头:['a', 'b']
result = {}
for item in csv_reader:
result[item["a"]] = item["b"]
print(result) # {'a1': 'b1', 'a2': 'b2'}
- 写
import csv
# 普通方式
# 如果要追加写入,则以“a”模式打开
# 不加newline每条数据中间会出现空行
with open("test.csv", "w", newline='') as csv_file:
csv_writer = csv.writer(csv_file)
# 定义表头
fieldnames = ["a","b"]
# 写入表头
csv_writer.writerow(fieldnames)
# 写入数据
csv_writer.writerow(['a1', 'b2'])
# 字典方式
with open("test.csv", "w", newline='') as csv_file:
# 定义表头
fieldnames = ["a","b"]
# delimiter参数可指定分隔符,默认为逗号
csv_writer = csv.DictWriter(csv_file, fieldnames=fieldnames)
# 写入表头
csv_writer.writeheader()
# 写入数据
csv_writer.writerow({"a":a1, "b":b1})