Python Pandas ValueError Arrays Must be All Same Length

Question

Iterates over a big list of .mp3 links to get the metadata tags and save it to an Excel file. Results in this error. I appreciate any help. Thanks.

    #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

you can do this to avoid that error

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

Explanation:

This creates the DataFrame as each key (e.g. 'Links') was a row and like this the missing values are actually missing columns which is no problem for pandas (only missing rows lead to ValueError during creation) After that you transpose the DataFrame (flip the axis) and make the rows to columns, which results the DataFrame you initially wanted.

Answer 2

It's telling you that the arrays (lines, titles, finalsingers, etc...) are not of the same length. You can test this by

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

This will show you which data is malformed and then you'll need to do some investigating into what the right way to correct this is.