麻烦Python列表

Question

以下代码旨在将一长串数字从csv转储到stat_by_symbol [symbol]，以便我可以使用每个符号作为键来调用数字列表。出于某种原因，代码似乎只适用于第一个符号。有人可以帮我修复代码按预期工作吗？非常感谢。

with open('zzdata.csv', 'rb') as f:
    reader = csv.reader(f)
    reader.next()
    for symbol in symbols:#symbols in a list
        stat = []
        for row in reader:
            if symbol in row:
                stat.append(row[8])#stat becomes long list of numbers
        stat_by_symbol[symbol] = [stat]

Answer 1

问题是你只能迭代reader一次（因此只是第一个符号匹配）。

试试这个：

stat_by_symbol = {}
with open('zzdata.csv', 'rb') as f:
    reader = csv.reader(f)
    reader.next()
    for row in reader:
        for symbol in symbols:#symbols in a list
            if symbol in row:
                stat_by_symbol.setdefault(symbol, []).append(row[8])