Improve dataframe data displaying ?

[halleygithub]

Refer to #1889 (comment)

And below is the completed code to do that. Can put it into the codebase and make it as the default option to display dataframe ?

def _sw(df, up_rows=10, down_rows=5, left_cols=4, right_cols=3):
''' display df data at four corners
A,B (up_pt)
C,D (down_pt)
parameters :
up_rows=10, down_rows=5, left_cols=4, right_cols=3
sample:
df = pd.DataFrame(np.random.randn(20,10), columns=list('ABCDEFGHIJKLMN')[0:10])
df.sw(5,2,3,2)
df1 = df.set_index(['A','B'], drop=True, inplace=False)
df1.sw(5,2,3,2)
'''

ncol, nrow = len(df.columns), len(df)

# handling columns
if ncol <= (left_cols + right_cols) :
    up_pt = df.ix[0:up_rows, :]         # screen width can contain all columns
    down_pt = df.ix[-down_rows:, :]
else:                                   # screen width can not contain all columns
    pt_a = df.ix[0:up_rows,  0:left_cols]
    pt_b = df.ix[0:up_rows,  -right_cols:]
    pt_c = df[-down_rows:].ix[:,0:left_cols]
    pt_d = df[-down_rows:].ix[:,-right_cols:]

    up_pt   = pt_a.join(pt_b, how='inner')
    down_pt = pt_c.join(pt_d, how='inner')
    up_pt.insert(left_cols, '..', '..')
    down_pt.insert(left_cols, '..', '..')

overlap_qty = len(up_pt) + len(down_pt) - len(df)
down_pt = down_pt.drop(down_pt.index[range(overlap_qty)]) # remove overlap rows

dt_str_list = down_pt.to_string().split('\n') # transfer down_pt to string list

# Display up part data
print up_pt

start_row = (1 if df.index.names[0] is None else 2) # start from 1 if without index

# Display omit line if screen height is not enought to display all rows
if overlap_qty < 0:
    print "." * len(dt_str_list[start_row])

# Display down part data row by row
for line in dt_str_list[start_row:]:
    print line

# Display foot note
print "\n"
print "Index :",df.index.names
print "Column:",",".join(list(df.columns.values))
print "row: %d    col: %d"%(len(df), len(df.columns))
print "\n"

return None

DataFrame.sw = _sw #add a method to DataFrame class

[sinhrks]

Same as #1889.