CODEWITHSUNDEEP
pythonpython-2.7pandas
TheOriginalBMan
TheOriginalBMan

Reputation: 237

Reshaping Pandas Data Frame

I'm parsing some HTML data using Pandas like this:

rankings = pd.read_html('https://en.wikipedia.org/wiki/Rankings_of_universities_in_the_United_Kingdom')
university_guide = rankings[0]

This gives me a nice data frame: enter image description here

What I want is to reshape this data frame so that there are only two columns (rank and university name). My current solution is to do something like this:

ug_copy = rankings[0][1:]
npa1 = ug_copy.as_matrix( columns=[0,1] )
npa2 = ug_copy.as_matrix( columns=[2,3] )
npa3 = ug_copy.as_matrix( columns=[4,5] )

npam = np.append(npa1,npa2)
npam = np.append(npam,npa3)

reshaped = npam.reshape((npam.size/2,2))

pd.DataFrame(data=reshaped)

This gives me what I want, but it doesn't seem like it could possibly be the best solution. I can't seem to find a good way to complete this all using a data frame. I've tried using stack/unstack and pivoting the data frame (as some of the other solutions here have suggested), but I haven't had any luck. I've tried doing something like this:

ug_copy.columns=['Rank','University','Rank','University','Rank','University']
ug_copy = ug_copy[1:]
ug_copy.groupby(['Rank', 'University'])

There has to be something small I'm missing!

Upvotes: 0

Views: 10134

Answers (1)

YS-L
YS-L

Reputation: 14738

This is probably a bit shorter (also note that you can use the header option in read_html to save a bit of work):

import pandas as pd
rankings = pd.read_html('https://en.wikipedia.org/wiki/Rankings_of_universities_in_the_United_Kingdom', header=0)
university_guide = rankings[0]
df = pd.DataFrame(university_guide.values.reshape((30, 2)), columns=['Rank', 'University'])
df = df.sort('Rank').reset_index(drop=True)
print df

Upvotes: 7

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