Pandas error in Python: columns must be same length as key

Question

I am webscraping some data from a few websites, and using pandas to modify it.

On the first few chunks of data it worked well, but later I get this error message:

Traceback(most recent call last):
  File "/home/web/.local/lib/python2.7/site-packages/pandas/core/frame.py, line 2326, in __setitem__ self._setitem_array(key,value)
  File "/home/web/.local/lib/python2.7/site-packages/pandas/core/frame.py, line 2350, in _setitem_array
raise ValueError("Columns must be same length as key')  ValueError: Columns must be same length as key

My code is here:

df2 = pd.DataFrame(datatable, columns = cols)
df2[['STATUS_ID_1','STATUS_ID_2']] = df2['STATUS'].str.split(n=1, expand=True)

My data looks like below:

                  STATUS
2       Landed   8:33 AM
3       Landed   9:37 AM
..         ...       ...
316    Delayed   5:00 PM
341    Delayed   4:32 PM
..         ...       ...
397    Delayed   5:23 PM
..         ...       ...

[240 rows x 2 columns]

Answer 1

You need a bit modify solution, because sometimes it return 2 and sometimes only one column:

df2 = pd.DataFrame({'STATUS':['Estimated 3:17 PM','Delayed 3:00 PM']})


df3 = df2['STATUS'].str.split(n=1, expand=True)
df3.columns = ['STATUS_ID{}'.format(x+1) for x in df3.columns]
print (df3)
  STATUS_ID1 STATUS_ID2
0  Estimated    3:17 PM
1    Delayed    3:00 PM

df2 = df2.join(df3)
print (df2)
              STATUS STATUS_ID1 STATUS_ID2
0  Estimated 3:17 PM  Estimated    3:17 PM
1    Delayed 3:00 PM    Delayed    3:00 PM

Another possible data - all data have no whitespaces and solution working too:

df2 = pd.DataFrame({'STATUS':['Canceled','Canceled']})

and solution return:

print (df2)
     STATUS STATUS_ID1
0  Canceled   Canceled
1  Canceled   Canceled

All together:

df3 = df2['STATUS'].str.split(n=1, expand=True)
df3.columns = ['STATUS_ID{}'.format(x+1) for x in df3.columns]
df2 = df2.join(df3)