Source code for param.ipython

Optional IPython extension for working with Parameters.

This extension offers extended but completely optional functionality
for IPython users.  From within IPython, it may be loaded using:

%load_ext param.ipython

This will register the %params line magic to allow easy inspection of
all the parameters defined on a parameterized class or object:

%params <parameterized class or object>

All parameters of the class or object will be listed in the IPython
pager together with all their corresponding attributes and
docstrings. Note that the class or object to be inspected must already
exist in the active namespace.

__author__ = "Jean-Luc Stevens"

import re
import sys
import itertools
import textwrap
import param

# Whether to generate warnings when misformatted docstrings are found

# ANSI color codes for the IPython pager
red   = '\x1b[1;31m%s\x1b[0m'
blue  = '\x1b[1;34m%s\x1b[0m'
green = '\x1b[1;32m%s\x1b[0m'
cyan = '\x1b[1;36m%s\x1b[0m'

[docs]class ParamPager(object): """ Callable class that displays information about the supplied Parameterized object or class in the IPython pager. """ def __init__(self, metaclass=False): """ If metaclass is set to True, the checks for Parameterized classes objects are disabled. This option is for use in ParameterizedMetaclass for automatic docstring generation. """ # Order of the information to be listed in the table (left to right) self.order = ['name', 'changed', 'value', 'type', 'bounds', 'mode'] self.metaclass = metaclass
[docs] def get_param_info(self, obj, include_super=True): """ Get the parameter dictionary, the list of modifed parameters and the dictionary of parameter values. If include_super is True, parameters are also collected from the super classes. """ params = dict(obj.param.objects('existing')) if isinstance(obj,type): changed = [] val_dict = dict((k,p.default) for (k,p) in params.items()) self_class = obj else: changed = list(obj.param.values(onlychanged=True).keys()) val_dict = obj.param.values() self_class = obj.__class__ if not include_super: params = dict((k,v) for (k,v) in params.items() if k in self_class.__dict__) params.pop('name') # Already displayed in the title. return (params, val_dict, changed)
[docs] def param_docstrings(self, info, max_col_len=100, only_changed=False): """ Build a string to that presents all of the parameter docstrings in a clean format (alternating red and blue for readability). """ (params, val_dict, changed) = info contents = [] displayed_params = [] for name in self.sort_by_precedence(params): if only_changed and not (name in changed): continue displayed_params.append((name, params[name])) right_shift = max(len(name) for name, _ in displayed_params)+2 for i, (name, p) in enumerate(displayed_params): heading = "%s: " % name unindented = textwrap.dedent("< No docstring available >" if p.doc is None else p.doc) if (WARN_MISFORMATTED_DOCSTRINGS and not unindented.startswith("\n") and len(unindented.splitlines()) > 1): param.main.warning("Multi-line docstring for %r is incorrectly formatted " " (should start with newline)", name) # Strip any starting newlines while unindented.startswith("\n"): unindented = unindented[1:] lines = unindented.splitlines() if len(lines) > 1: tail = ['%s%s' % (' ' * right_shift, line) for line in lines[1:]] all_lines = [ heading.ljust(right_shift) + lines[0]] + tail elif len(lines) == 1: all_lines = [ heading.ljust(right_shift) + lines[0]] else: all_lines = [] if i % 2: # Alternate red and blue for docstrings contents.extend([red %el for el in all_lines]) else: contents.extend([blue %el for el in all_lines]) return "\n".join(contents)
[docs] def sort_by_precedence(self, parameters): """ Sort the provided dictionary of parameters by their precedence value. In Python 3, preserves the original ordering for parameters with the same precedence; for Python 2 sorts them lexicographically by name, unless explicit precedences are provided. """ params = [(p, pobj) for p, pobj in parameters.items()] key_fn = lambda x: x[1].precedence if x[1].precedence is not None else 1e-8 sorted_params = sorted(params, key=key_fn) groups = itertools.groupby(sorted_params, key=key_fn) # Params preserve definition order in Python 3.6+ dict_ordered = ( (sys.version_info.major == 3 and sys.version_info.minor >= 6) or (sys.version_info.major > 3) or all(p.precedence is not None for p in parameters.values()) ) ordered_groups = [list(grp) if dict_ordered else sorted(grp) for (_, grp) in groups] ordered_params = [el[0] for group in ordered_groups for el in group if (el[0] != 'name' or el[0] in parameters)] return ordered_params
def _build_table(self, info, order, max_col_len=40, only_changed=False): """ Collect the information about parameters needed to build a properly formatted table and then tabulate it. """ info_list, bounds_dict = [], {} (params, val_dict, changed) = info col_widths = dict((k,0) for k in order) ordering = self.sort_by_precedence(params) for name in ordering: p = params[name] if only_changed and not (name in changed): continue constant = 'C' if p.constant else 'V' readonly = 'RO' if p.readonly else 'RW' allow_None = ' AN' if hasattr(p, 'allow_None') and p.allow_None else '' mode = '%s %s%s' % (constant, readonly, allow_None) value = repr(val_dict[name]) if len(value) > (max_col_len - 3): value = value[:max_col_len-3] + '...' p_dict = {'name': name, 'type': p.__class__.__name__, 'mode': mode, 'value': value} if hasattr(p, 'bounds'): lbound, ubound = (None,None) if p.bounds is None else p.bounds mark_lbound, mark_ubound = False, False # Use soft_bounds when bounds not defined. if hasattr(p, 'get_soft_bounds'): soft_lbound, soft_ubound = p.get_soft_bounds() if lbound is None and soft_lbound is not None: lbound = soft_lbound mark_lbound = True if ubound is None and soft_ubound is not None: ubound = soft_ubound mark_ubound = True if (lbound, ubound) != (None,None): bounds_dict[name] = (mark_lbound, mark_ubound) p_dict['bounds'] = '(%s, %s)' % (lbound, ubound) for col in p_dict: max_width = max([col_widths[col], len(p_dict[col])]) col_widths[col] = max_width info_list.append((name, p_dict)) return self._tabulate(info_list, col_widths, changed, order, bounds_dict) def _tabulate(self, info_list, col_widths, changed, order, bounds_dict): """ Returns the supplied information as a table suitable for printing or paging. info_list: List of the parameters name, type and mode. col_widths: Dictionary of column widths in characters changed: List of parameters modified from their defaults. order: The order of the table columns bound_dict: Dictionary of appropriately formatted bounds """ contents, tail = [], [] column_set = set(k for _, row in info_list for k in row) columns = [col for col in order if col in column_set] title_row = [] # Generate the column headings for i, col in enumerate(columns): width = col_widths[col]+2 col = col.capitalize() formatted = col.ljust(width) if i == 0 else title_row.append(formatted) contents.append(blue % ''.join(title_row)+"\n") # Format the table rows for row, info in info_list: row_list = [] for i,col in enumerate(columns): width = col_widths[col]+2 val = info[col] if (col in info) else '' formatted = val.ljust(width) if i==0 else if col == 'bounds' and bounds_dict.get(row,False): (mark_lbound, mark_ubound) = bounds_dict[row] lval, uval = formatted.rsplit(',') lspace, lstr = lval.rsplit('(') ustr, uspace = uval.rsplit(')') lbound = lspace + '('+(cyan % lstr) if mark_lbound else lval ubound = (cyan % ustr)+')'+uspace if mark_ubound else uval formatted = "%s,%s" % (lbound, ubound) row_list.append(formatted) row_text = ''.join(row_list) if row in changed: row_text = red % row_text contents.append(row_text) return '\n'.join(contents+tail) def __call__(self, param_obj): """ Given a Parameterized object or class, display information about the parameters in the IPython pager. """ title = None if not self.metaclass: parameterized_object = isinstance(param_obj, param.Parameterized) parameterized_class = (isinstance(param_obj,type) and issubclass(param_obj,param.Parameterized)) if not (parameterized_object or parameterized_class): print("Object is not a Parameterized class or object.") return if parameterized_object: # Only show the name if not autogenerated class_name = param_obj.__class__.__name__ default_name = re.match('^'+class_name+'[0-9]+$', obj_name = '' if default_name else (' %r' % title = 'Parameters of %r instance%s' % (class_name, obj_name) if title is None: title = 'Parameters of %r' % heading_line = '=' * len(title) heading_text = "%s\n%s\n" % (title, heading_line) param_info = self.get_param_info(param_obj, include_super=True) if not param_info[0]: return "%s\n%s" % ((green % heading_text), "Object has no parameters.") table = self._build_table(param_info, self.order, max_col_len=40, only_changed=False) docstrings = self.param_docstrings(param_info, max_col_len=100, only_changed=False) dflt_msg = "Parameters changed from their default values are marked in red." top_heading = (green % heading_text) top_heading += "\n%s" % (red % dflt_msg) top_heading += "\n%s" % (cyan % "Soft bound values are marked in cyan.") top_heading += '\nC/V= Constant/Variable, RO/RW = ReadOnly/ReadWrite, AN=Allow None' heading_text = 'Parameter docstrings:' heading_string = "%s\n%s" % (heading_text, '=' * len(heading_text)) docstring_heading = (green % heading_string) return "%s\n\n%s\n\n%s\n\n%s" % (top_heading, table, docstring_heading, docstrings)
message = """Welcome to the param IPython extension! (""" message += '\nAvailable magics: %params' _loaded = False def load_ipython_extension(ip, verbose=True): from IPython.core.magic import Magics, magics_class, line_magic from IPython.core import page @magics_class class ParamMagics(Magics): """ Implements the %params line magic used to inspect the parameters of a parameterized class or object. """ def __init__(self, *args, **kwargs): super(ParamMagics, self).__init__(*args, **kwargs) self.param_pager = ParamPager() @line_magic def params(self, parameter_s='', namespaces=None): """ The %params line magic accepts a single argument which is a handle on the parameterized object to be inspected. If the object can be found in the active namespace, information about the object's parameters is displayed in the IPython pager. Usage: %params <parameterized class or object> """ if parameter_s=='': print("Please specify an object to inspect.") return # Beware! Uses IPython internals that may change in future... obj = if obj.found is False: print("Object %r not found in the namespace." % parameter_s) return if verbose: print(message) global _loaded if not _loaded: _loaded = True ip.register_magics(ParamMagics)