循环遍历一个csv文件的行以在另一个csv文件中查找相应的数据

Question

我遇到了一个有趣的问题:

file1.csv有几百行,如:

Code,DTime
1,2010-12-26 17:01
2,2010-12-26 17:07
2,2010-12-26 17:15

file2.csv有大约1,100万行,如:

id,D,Sym,DateTime,Bid,Ask
1375022797,D,USD,2010-12-26 17:00:15,1.311400,1.311700
1375022965,D,USD,2010-12-26 17:00:56,1.311200,1.311500
1375022984,D,USD,2010-12-26 17:00:56,1.311300,1.311600
1375023013,D,USD,2010-12-26 17:01:01,1.311200,1.311500
1375023039,D,USD,2010-12-26 17:01:02,1.311100,1.311400
1375023055,D,USD,2010-12-26 17:01:03,1.311200,1.311500
1375023063,D,USD,2010-12-26 17:01:03,1.311300,1.311600

我要做的是编写一个脚本,该文件获取file1.csv中的每个DTime值,并在file2.csv的DateTime列中找到部分匹配的第一个实例,并输出DateTime,Bid,Ask for该行.部分匹配在前16个字符上.

这两个文件都从最旧到最新排序,所以如果file1.csv中的"2010-12-26 17:01"匹配file2.csv中的4个条目,我只需要提取第一个:"2010-12-26 17: 01:01"

不确定如何继续..我尝试了字典,但值的顺序很重要,所以我不确定这是否有效.也许将file1的DTime列放入列表中,对于该列表中的每个条目,在file2中搜索DateTime？

多谢你们

Answer 1

如果您没有重复DTime值,这应该有效:

import csv

file1reader = csv.reader(open("file1.csv"), delimiter=",")
file2reader = csv.reader(open("file2.csv"), delimiter=",")

header1 = file1reader.next() #header
header2 = file2reader.next() #header

for Code, DTime in file1reader:
    for id_, D, Sym, DateTime, Bid, Ask in file2reader:
        if DateTime.startswith(DTime): # found it
            print DateTime, Bid, Ask   # output data
            break                      # break and continue where we left next time

编辑

import csv
from datetime import datetime

file1reader = csv.reader(open("file1.csv"), delimiter=",")
file2reader = csv.reader(open("file2.csv"), delimiter=",")

header1 = file1reader.next() #header
header2 = file2reader.next() #header

for Code, DTime in file1reader:
    DTime = datetime.strptime(DTime, "%Y-%m-%d %H:%M")
    for id_, D, Sym, DateTime, Bid, Ask in file2reader:
        DateTime = datetime.strptime(DateTime, "%Y-%m-%d %H:%M:%S")
        if DateTime>=DTime: # found it
            print DateTime, Bid, Ask   # output data
            break                      # break and continue where we left next time