Python Pandas ValueError 數組的長度必須相同

Question

遍歷大量 .mp3 鏈接以獲取元數據標簽並將其保存到 Excel 文件中。 導致此錯誤。 我很感激任何幫助。 謝謝。

    #print is_connected();

    # Create a Pandas dataframe from the data.
df = pd.DataFrame({'Links' : lines ,'Titles' : titles , 'Singers': finalsingers , 'Albums':finalalbums , 'Years' : years})


    # Create a Pandas Excel writer using XlsxWriter as the engine.
writer = pd.ExcelWriter(xlspath, engine='xlsxwriter')

    # Convert the dataframe to an XlsxWriter Excel object.
df.to_excel(writer, sheet_name='Sheet1')
    #df.to_excel(writer, sheet_name='Sheet1')


    # Close the Pandas Excel writer and output the Excel file.
writer.save()

Traceback (most recent call last):
  File "mp.py", line 87, in <module>
    df = pd.DataFrame({'Links' : lines ,'Titles' : titles , 'Singers': finalsingers , 'Albums':finalalbums , 'Years' : years})
  File "C:\Python27\lib\site-packages\pandas\core\frame.py", line 266, in __init__
    mgr = self._init_dict(data, index, columns, dtype=dtype)
  File "C:\Python27\lib\site-packages\pandas\core\frame.py", line 402, in _init_dict
    return _arrays_to_mgr(arrays, data_names, index, columns, dtype=dtype)
  File "C:\Python27\lib\site-packages\pandas\core\frame.py", line 5409, in _arrays_to_mgr
    index = extract_index(arrays)
  File "C:\Python27\lib\site-packages\pandas\core\frame.py", line 5457, in extract_index
    raise ValueError('arrays must all be same length')
ValueError: arrays must all be same length

Answer 1

您可以這樣做以避免該錯誤

a = {'Links' : lines ,'Titles' : titles , 'Singers': finalsingers , 'Albums':finalalbums , 'Years' : years}
df = pd.DataFrame.from_dict(a, orient='index')
df = df.transpose()

Answer 2

它告訴您數組（行、標題、finalsingers 等）的長度不同。 您可以通過以下方式測試

print(len(lines), len(titles), len(finalsingers)) # Print all of them out here

這將向您顯示哪些數據格式不正確，然后您需要進行一些調查以了解糾正此錯誤的正確方法是什么。

Answer 3

您可以用空元素填充最短的列表：

def pad_dict_list(dict_list, padel):
    lmax = 0
    for lname in dict_list.keys():
        lmax = max(lmax, len(dict_list[lname]))
    for lname in dict_list.keys():
        ll = len(dict_list[lname])
        if  ll < lmax:
            dict_list[lname] += [padel] * (lmax - ll)
    return dict_list

Answer 4

重復的變量名給我造成了這個問題

Answer 5

我在將 JSON 文件讀取到 Pandas 框架時遇到了同樣的錯誤。 添加linesbool，默認False參數解決了這個問題。

StringData = StringIO(obj.get()['Body'].read().decode('utf-8'))
                mydata = pdf.read_json(StringData, lines=True)