循环以在Python中将多个列表追加到单个列表 [英] Loop to append multiple lists to a single list in Python

问题描述

在下面的代码中，行[8]，行[9]，...，行[27]每个都包含许多数字.我需要将row [8]，row [9]等中的所有数字附加到stat_by_symbol中，作为stat_by_symbol中的单独列表.但是，下面的代码将所有数字附加在单个列表的所有行中.

In the following code, row[8], row[9], ..., row[27] each contain many numbers. I need all of the numbers in row[8], row[9], etc. to append to stat_by_symbol as separate lists within within stat_by_symbol. However, the code below appends all of the numbers across all rows within a single list.

作为我所需要的示例，如果我叫stat_by_symbol ['aaa'] [0]，则应该从行[8]中提取数字列表.

As an example of what I need, if I called stat_by_symbol['aaa'][0], then I should get the list of numbers pulled from row[8].

我该如何解决?非常感谢.

How can I fix this? Many thanks.

编辑以进一步说明.我已经附上了csv的快照.我需要stat_by_symbol ['aaa'] [0]给我第i列下的所有数字.同样，具有索引1的stat_by_symbol将为我提供第j列下的所有数字.

EDIT for further clarification. I've attached a snapshot of the csv. I need stat_by_symbol['aaa'][0] to give me all of the numbers under Column i. Similarly, stat_by_symbol with index 1 would give me all of the numbers under Column j.

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:
                for i in range(8, 28):
                    stat_by_symbol.setdefault(symbol, []).append(row[i])

推荐答案

stat_by_symbol = dict((symbol, [[] for i in xrange(8,28)]) for symbol in symbols)
with open('zzdata.csv', 'rb') as f:
    reader = csv.reader(f)
    reader.next()
    for row in reader:
        for symbol, symbol_list in stat_by_symbol.iteritems():
            if symbol in row:
                for symbol_list2, cell in zip(symbol_list, row[8:28]):
                    symbol_list2.append(cell)

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