Question

经过几周的精炼之后，我得到了以下代码，感谢SO上的精彩人员根据需要生成数据帧，但我不知道如何将程序中的数据帧连接成最终的数据帧对象变量。我只是将concat语句分配给变量，然后我最终得到最后一个数据帧。

{
"zipcode":"08989",
"current" {"canwc":null,"cig":4900,"class":"observation","clds":"OVC","day_ind":"D","dewpt":19,"expireTimeGMT":1385486700,"feels_like":34,"gust":null,"hi":37,"humidex":null,"icon_code":26,"icon_extd":2600,"max_temp":37,"wxMan":"wx1111"},
"triggers":[53,31,9,21,48,7,40,178,55,179,176,26,103,175,33,51,20,57,112,30,50,113]
}
{
"zipcode":"08990",
"current":{"canwc":null,"cig":4900,"class":"observation","clds":"OVC","day_ind":"D","dewpt":19,"expireTimeGMT":1385486700,"feels_like":34,"gust":null,"hi":37,"humidex":null,"icon_code":26,"icon_extd":2600,"max_temp":37, "wxMan":"wx1111"},
"triggers":[53,31,9,21,48,7,40,178,55,179,176,26,103,175,33,51,20,57,112,30,50,113]
}

def lines_per_n(f, n):
    for line in f:
        yield ''.join(chain([line], itertools.islice(f, n - 1)))

def series_chunk(chunk):
    try:
        jfile = json.loads(chunk)
        zipcode = jfile['zipcode']
        datetime = jfile['current']['proc_time']
        triggers = jfile['triggers']
        return pd.Series([jfile['zipcode'], jfile['current']['proc_time'],\
                            jfile['triggers']])
    except ValueError, e:
        pass
    else:
        pass

for fin in glob.glob('*.txt'):
    with open(fin) as f:
        print pd.concat([series_chunk(chunk) for chunk in lines_per_n(f, 5)], axis=1).T

从上面的程序输出，我需要作为一个数据帧连接：

       0               1                                                  2
0  08988  20131126102946                                                 []
1  08989  20131126102946  [53, 31, 9, 21, 48, 7, 40, 178, 55, 179, 176, ...
       0               1                                                  2
0  08988  20131126102946                                                 []
1  08989  20131126102946  [53, 31, 9, 21, 48, 7, 40, 178, 55, 179, 176, ...

最后将此归结为提交。以下是完成我需要的最终代码：

dfs = []
for fin in glob.glob('*.txt'):
    with open(fin) as f:
        df = pd.concat([series_chunk(chunk) for\
            chunk in lines_per_n(f, 7)], axis=1).T
        dfs.append(df)

df = pd.concat(dfs, ignore_index=True)

Answer 1

很高兴你对此进行了分类。 IMO是一种稍微更清晰的方式来做这个列表理解

def dataframe_from_file(fin):
    with open(fin) as f:
        return pd.concat([series_chunk(chunk) for chunk in lines_per_n(f, 7)],
                            axis=1).T

df = pd.concat([dataframe_from_file(fin) for fin in glob.glob('*.txt')],
                  ignore_index=True)

注意：使用axis = 1进行最终连接可能意味着您可以提前避免使用T-ing。

将Python Pandas Dataframe输出从程序组合到一个Dataframe中

1 个答案: