Permalink
Find file
Fetching contributors…
Cannot retrieve contributors at this time
executable file 78 lines (56 sloc) 2 KB
#!/usr/bin/env python
"""
Simple, ctypes-based Python 2/3 interface to C API of xylib.
It would be possible to wrap it neatly in classes,
or to make bindings to C++ API of xylib,
but it is not planned due to low demand.
"""
from __future__ import print_function
from ctypes import cdll, c_char_p, c_double
import os
_dll_path = 'libxy.so.4' # platform-dependent actually
lib = cdll.LoadLibrary(_dll_path)
get_version = lib.xylib_get_version
get_version.restype = c_char_p
load_file = lib.xylib_load_file
get_block = lib.xylib_get_block
count_columns = lib.xylib_count_columns
count_rows = lib.xylib_count_rows
get_data = lib.xylib_get_data
get_data.restype = c_double
dataset_metadata = lib.xylib_dataset_metadata
dataset_metadata.restype = c_char_p
block_metadata = lib.xylib_block_metadata
block_metadata.restype = c_char_p
free_dataset = lib.xylib_free_dataset
# Usage example. Can be tested as "./xylib_capi.py my-file".
def _print_info(filename):
if hasattr(filename, 'encode'):
filename = filename.encode('utf-8')
dataset = load_file(filename, None, None)
if not dataset:
sys.exit('File not found: %s' % filename)
block = get_block(dataset, 0)
ncol = count_columns(block)
print('number of columns:', ncol)
print('column lengths (-1 means a generator): ', end='')
for i in range(ncol):
print(count_rows(block, i+1), end='')
n = min(count_rows(block, 2), 20)
print('\ndata:',
' '.join('(%g, %g)' % (get_data(block, 1, i), get_data(block, 2, i))
for i in range(n)),
'...')
# metadata is file-format specific
measure_date = dataset_metadata(dataset, 'MEASURE_DATE')
if measure_date:
print('measured at:', measure_date)
used_lambda = block_metadata(block, 'USED_LAMBDA')
if used_lambda:
print('lambda:', used_lambda)
free_dataset(dataset)
if __name__ == '__main__':
import sys
print('xylib version:', get_version())
for arg in sys.argv[1:]:
_print_info(arg)