user  document
0  john      book
1  jane   article
2  jane      book
3  jane      book
4   jim   article
5  john      book
6   jim  blogpost
7  jane  blogpost
8  jane  blogpost
9  jane  blogpost

blogpost  article  book
john         1        3     0
jane         0        0     1
jim          4        0     2

df = pd.DataFrame(index=users, columns=documents)
df.fillna(0, inplace=True)

grouped = records.groupby(['user', 'document'])
for elem in grouped:
    user, document = elem[0]
    downloads = len(elem[1])
    df.loc[user, document] = downloads

records = pd.DataFrame([
    ('john', 'book'),
    ('jane', 'article'),
    ('jane','book'),
    ('jane','book'),
    ('jim', 'article'),
    ('john', 'book'),
    ('jim', 'blogpost'),
    ('jane', 'blogpost'),
    ('jane', 'blogpost'),
    ('jane', 'blogpost')
    ], columns=['user', 'document'])
print(records)

users = list(set(records['user']))
users.sort()
documents = list(set(records['document']))
documents.sort()

print(users)
print(documents)

df = pd.DataFrame(index=users, columns=documents)
df.fillna(0, inplace=True)
print(df)

grouped = records.groupby(['user', 'document'])
for elem in grouped:
    user, document = elem[0]
    downloads = len(elem[1])
    df.loc[user, document] = downloads