有没有办法在指定的行启动 DictReader？

Question

我想打开一个读取器对象并进行集成，直到匹配“事务日期”，在这种情况下使用 DictReader 来获取一个 dict 对象。

starting=0
with open(argv[1], 'r')as file:
    transaction = list(csv.reader(file))
    #what line is the dictReader on?
    counter=0
    for line in transaction:
        counter+=1
        if line[0]=='Transaction Date':
            starting=counter-1
    
    a=csv.DictReader(file)
    
    for b in a:
        print(b)

编辑：解决方案

    file=open(argv[1],'r')
    #go to that line
    for i in range(starting):
        file.readline()
        
    #read in as dict
    dict=list(csv.DictReader(file))

Answer 1

你可以使用itertools.dropwhile，类似

from itertools import dropwhile


def f(line):
    return line[0] != 'Transaction Date'


with open(argv[1], 'r') as file:
    transaction = dropwhile(f, csv.reader(file))
    for b in transaction:
        print(b)

Answer 2

从一个 DictReader 开始；在 while 循环中检查每个 row 直到满足您的条件；然后使用 for 循环进行迭代以处理其余部分。

import io, csv

data = '''col_a,col_b
transaction week,4
transaction second,5
transaction date,6
foo,7
bar,8
the end,9
'''
with io.StringIO(data) as f:
    reader = csv.DictReader(f)
    row = next(reader)
    while row['col_a'] != 'transaction date':
        row = next(reader)
    for row in reader:
        print(row)