从CSV文件创建字典

创建一个字典，然后遍历结果并将行填充到字典中。请注意，如果遇到日期重复的行，则必须决定要执行的操作（引发异常，替换上一行，丢弃下一行等）。

这是test.csv：

Date,Foo,Bar123,456,789abc,def,ghi

和相应的程序：

import csvreader = csv.reader(open('test.csv'))result = {}for row in reader:    key = row[0]    if key in result:        # implement your duplicate row handling here        pass    result[key] = row[1:]print(result)

产量：

{'Date': ['Foo', 'Bar'], '123': ['456', '789'], 'abc': ['def', 'ghi']}

或者，使用DictReader：

import csvreader = csv.DictReader(open('test.csv'))result = {}for row in reader:    key = row.pop('Date')    if key in result:        # implement your duplicate row handling here        pass    result[key] = rowprint(result)

结果是：

{'123': {'Foo': '456', 'Bar': '789'}, 'abc': {'Foo': 'def', 'Bar': 'ghi'}}

或者，您可能希望将列标题映射到该列的值列表：

import csvreader = csv.DictReader(open('test.csv'))result = {}for row in reader:    for column, value in row.items():  # consider .iteritems() for Python 2        result.setdefault(column, []).append(value)print(result)

产生：

{'Date': ['123', 'abc'], 'Foo': ['456', 'def'], 'Bar': ['789', 'ghi']}