if hasattr(query_or_op, 'operations'):

explain(query_or_op.operations)

return

op = query_or_op

p = []

if indent:

p.append('+')

p.append(("-" * indent) + op.__class__.__name__)

p.append("(")

params = []

for name in op.__slots__:

if name not in ('left', 'right', 'relation'):

params.append("{}={}".format(name, getattr(op, name)))

p.append(",".join(params))

p.append(")")

print "".join(p)

if isinstance(op,JoinOp):

explain(op.left, indent+1)

explain(op.right, indent+1)

elif not isinstance(op, LoadOp):

width,height = term_size()

table = Texttable(width)

sample, iterator = tee(relation)

table.add_rows(take(1000,sample))

table._compute_cols_width()

del sample

table.reset()

table.set_deco(Texttable.HEADER)

table.header([f.name for f in relation.schema.fields])

rows = take(height-3, iterator)

try:

while rows:

table.add_rows(rows, header=False)

print table.draw()

rows = take(height-3, iterator)

if rows:

raw_input("-- enter for more ^c to quit --")

except KeyboardInterrupt:

import os

env = os.environ

def ioctl_GWINSZ(fd):

try:

import fcntl, termios, struct, os

cr = struct.unpack('hh', fcntl.ioctl(fd, termios.TIOCGWINSZ,

'1234'))

except:

return

return cr

cr = ioctl_GWINSZ(0) or ioctl_GWINSZ(1) or ioctl_GWINSZ(2)

if not cr:

try:

fd = os.open(os.ctermid(), os.O_RDONLY)

cr = ioctl_GWINSZ(fd)

os.close(fd)

except:

pass

if not cr:

cr = (env.get('LINES', 25), env.get('COLUMNS', 80))