Source code for astropy.table.pprint

# Licensed under a 3-clause BSD style license - see LICENSE.rst

import os
import sys
import re

import numpy as np

from astropy import log
from astropy.utils.console import Getch, color_print, terminal_size, conf
from astropy.utils.data_info import dtype_info_name

__all__ = []


def default_format_func(format_, val):
    if isinstance(val, bytes):
        return val.decode('utf-8', errors='replace')
    else:
        return str(val)


# The first three functions are helpers for _auto_format_func

def _use_str_for_masked_values(format_func):
    """Wrap format function to trap masked values.

    String format functions and most user functions will not be able to deal
    with masked values, so we wrap them to ensure they are passed to str().
    """
    return lambda format_, val: (str(val) if val is np.ma.masked
                                 else format_func(format_, val))


def _possible_string_format_functions(format_):
    """Iterate through possible string-derived format functions.

    A string can either be a format specifier for the format built-in,
    a new-style format string, or an old-style format string.
    """
    yield lambda format_, val: format(val, format_)
    yield lambda format_, val: format_.format(val)
    yield lambda format_, val: format_ % val


def get_auto_format_func(
        col=None,
        possible_string_format_functions=_possible_string_format_functions):
    """
    Return a wrapped ``auto_format_func`` function which is used in
    formatting table columns.  This is primarily an internal function but
    gets used directly in other parts of astropy, e.g. `astropy.io.ascii`.

    Parameters
    ----------
    col_name : object, optional
        Hashable object to identify column like id or name. Default is None.

    possible_string_format_functions : func, optional
        Function that yields possible string formatting functions
        (defaults to internal function to do this).

    Returns
    -------
    Wrapped ``auto_format_func`` function
    """

    def _auto_format_func(format_, val):
        """Format ``val`` according to ``format_`` for a plain format specifier,
        old- or new-style format strings, or using a user supplied function.
        More importantly, determine and cache (in _format_funcs) a function
        that will do this subsequently.  In this way this complicated logic is
        only done for the first value.

        Returns the formatted value.
        """
        if format_ is None:
            return default_format_func(format_, val)

        if format_ in col.info._format_funcs:
            return col.info._format_funcs[format_](format_, val)

        if callable(format_):
            format_func = lambda format_, val: format_(val)
            try:
                out = format_func(format_, val)
                if not isinstance(out, str):
                    raise ValueError('Format function for value {} returned {} '
                                     'instead of string type'
                                     .format(val, type(val)))
            except Exception as err:
                # For a masked element, the format function call likely failed
                # to handle it.  Just return the string representation for now,
                # and retry when a non-masked value comes along.
                if val is np.ma.masked:
                    return str(val)

                raise ValueError('Format function for value {} failed: {}'
                                 .format(val, err))
            # If the user-supplied function handles formatting masked elements, use
            # it directly.  Otherwise, wrap it in a function that traps them.
            try:
                format_func(format_, np.ma.masked)
            except Exception:
                format_func = _use_str_for_masked_values(format_func)
        else:
            # For a masked element, we cannot set string-based format functions yet,
            # as all tests below will fail.  Just return the string representation
            # of masked for now, and retry when a non-masked value comes along.
            if val is np.ma.masked:
                return str(val)

            for format_func in possible_string_format_functions(format_):
                try:
                    # Does this string format method work?
                    out = format_func(format_, val)
                    # Require that the format statement actually did something.
                    if out == format_:
                        raise ValueError('the format passed in did nothing.')
                except Exception:
                    continue
                else:
                    break
            else:
                # None of the possible string functions passed muster.
                raise ValueError('unable to parse format string {} for its '
                                 'column.'.format(format_))

            # String-based format functions will fail on masked elements;
            # wrap them in a function that traps them.
            format_func = _use_str_for_masked_values(format_func)

        col.info._format_funcs[format_] = format_func
        return out

    return _auto_format_func


[docs]class TableFormatter: @staticmethod def _get_pprint_size(max_lines=None, max_width=None): """Get the output size (number of lines and character width) for Column and Table pformat/pprint methods. If no value of ``max_lines`` is supplied then the height of the screen terminal is used to set ``max_lines``. If the terminal height cannot be determined then the default will be determined using the ``astropy.table.conf.max_lines`` configuration item. If a negative value of ``max_lines`` is supplied then there is no line limit applied. The same applies for max_width except the configuration item is ``astropy.table.conf.max_width``. Parameters ---------- max_lines : int or None Maximum lines of output (header + data rows) max_width : int or None Maximum width (characters) output Returns ------- max_lines, max_width : int """ if max_lines is None: max_lines = conf.max_lines if max_width is None: max_width = conf.max_width if max_lines is None or max_width is None: lines, width = terminal_size() if max_lines is None: max_lines = lines elif max_lines < 0: max_lines = sys.maxsize if max_lines < 8: max_lines = 8 if max_width is None: max_width = width elif max_width < 0: max_width = sys.maxsize if max_width < 10: max_width = 10 return max_lines, max_width def _pformat_col(self, col, max_lines=None, show_name=True, show_unit=None, show_dtype=False, show_length=None, html=False, align=None): """Return a list of formatted string representation of column values. Parameters ---------- max_lines : int Maximum lines of output (header + data rows) show_name : bool Include column name. Default is True. show_unit : bool Include a header row for unit. Default is to show a row for units only if one or more columns has a defined value for the unit. show_dtype : bool Include column dtype. Default is False. show_length : bool Include column length at end. Default is to show this only if the column is not shown completely. html : bool Output column as HTML align : str Left/right alignment of columns. Default is '>' (right) for all columns. Other allowed values are '<', '^', and '0=' for left, centered, and 0-padded, respectively. Returns ------- lines : list List of lines with formatted column values outs : dict Dict which is used to pass back additional values defined within the iterator. """ if show_unit is None: show_unit = col.info.unit is not None outs = {} # Some values from _pformat_col_iter iterator that are needed here col_strs_iter = self._pformat_col_iter(col, max_lines, show_name=show_name, show_unit=show_unit, show_dtype=show_dtype, show_length=show_length, outs=outs) col_strs = list(col_strs_iter) if len(col_strs) > 0: col_width = max(len(x) for x in col_strs) if html: from astropy.utils.xml.writer import xml_escape n_header = outs['n_header'] for i, col_str in enumerate(col_strs): # _pformat_col output has a header line '----' which is not needed here if i == n_header - 1: continue td = 'th' if i < n_header else 'td' val = '<{}>{}</{}>'.format(td, xml_escape(col_str.strip()), td) row = ('<tr>' + val + '</tr>') if i < n_header: row = ('<thead>' + row + '</thead>') col_strs[i] = row if n_header > 0: # Get rid of '---' header line col_strs.pop(n_header - 1) col_strs.insert(0, '<table>') col_strs.append('</table>') # Now bring all the column string values to the same fixed width else: col_width = max(len(x) for x in col_strs) if col_strs else 1 # Center line header content and generate dashed headerline for i in outs['i_centers']: col_strs[i] = col_strs[i].center(col_width) if outs['i_dashes'] is not None: col_strs[outs['i_dashes']] = '-' * col_width # Format columns according to alignment. `align` arg has precedent, otherwise # use `col.format` if it starts as a legal alignment string. If neither applies # then right justify. re_fill_align = re.compile(r'(?P<fill>.?)(?P<align>[<^>=])') match = None if align: # If there is an align specified then it must match match = re_fill_align.match(align) if not match: raise ValueError("column align must be one of '<', '^', '>', or '='") elif isinstance(col.info.format, str): # col.info.format need not match, in which case rjust gets used match = re_fill_align.match(col.info.format) if match: fill_char = match.group('fill') align_char = match.group('align') if align_char == '=': if fill_char != '0': raise ValueError("fill character must be '0' for '=' align") fill_char = '' # str.zfill gets used which does not take fill char arg else: fill_char = '' align_char = '>' justify_methods = {'<': 'ljust', '^': 'center', '>': 'rjust', '=': 'zfill'} justify_method = justify_methods[align_char] justify_args = (col_width, fill_char) if fill_char else (col_width,) for i, col_str in enumerate(col_strs): col_strs[i] = getattr(col_str, justify_method)(*justify_args) if outs['show_length']: col_strs.append('Length = {} rows'.format(len(col))) return col_strs, outs def _pformat_col_iter(self, col, max_lines, show_name, show_unit, outs, show_dtype=False, show_length=None): """Iterator which yields formatted string representation of column values. Parameters ---------- max_lines : int Maximum lines of output (header + data rows) show_name : bool Include column name. Default is True. show_unit : bool Include a header row for unit. Default is to show a row for units only if one or more columns has a defined value for the unit. outs : dict Must be a dict which is used to pass back additional values defined within the iterator. show_dtype : bool Include column dtype. Default is False. show_length : bool Include column length at end. Default is to show this only if the column is not shown completely. """ max_lines, _ = self._get_pprint_size(max_lines, -1) multidims = getattr(col, 'shape', [0])[1:] if multidims: multidim0 = tuple(0 for n in multidims) multidim1 = tuple(n - 1 for n in multidims) trivial_multidims = np.prod(multidims) == 1 i_dashes = None i_centers = [] # Line indexes where content should be centered n_header = 0 if show_name: i_centers.append(n_header) # Get column name (or 'None' if not set) col_name = str(col.info.name) if multidims: col_name += ' [{}]'.format( ','.join(str(n) for n in multidims)) n_header += 1 yield col_name if show_unit: i_centers.append(n_header) n_header += 1 yield str(col.info.unit or '') if show_dtype: i_centers.append(n_header) n_header += 1 try: dtype = dtype_info_name(col.dtype) except AttributeError: dtype = 'object' yield str(dtype) if show_unit or show_name or show_dtype: i_dashes = n_header n_header += 1 yield '---' max_lines -= n_header n_print2 = max_lines // 2 n_rows = len(col) # This block of code is responsible for producing the function that # will format values for this column. The ``format_func`` function # takes two args (col_format, val) and returns the string-formatted # version. Some points to understand: # # - col_format could itself be the formatting function, so it will # actually end up being called with itself as the first arg. In # this case the function is expected to ignore its first arg. # # - auto_format_func is a function that gets called on the first # column value that is being formatted. It then determines an # appropriate formatting function given the actual value to be # formatted. This might be deterministic or it might involve # try/except. The latter allows for different string formatting # options like %f or {:5.3f}. When auto_format_func is called it: # 1. Caches the function in the _format_funcs dict so for subsequent # values the right function is called right away. # 2. Returns the formatted value. # # - possible_string_format_functions is a function that yields a # succession of functions that might successfully format the # value. There is a default, but Mixin methods can override this. # See Quantity for an example. # # - get_auto_format_func() returns a wrapped version of auto_format_func # with the column id and possible_string_format_functions as # enclosed variables. col_format = col.info.format or getattr(col.info, 'default_format', None) pssf = (getattr(col.info, 'possible_string_format_functions', None) or _possible_string_format_functions) auto_format_func = get_auto_format_func(col, pssf) format_func = col.info._format_funcs.get(col_format, auto_format_func) if len(col) > max_lines: if show_length is None: show_length = True i0 = n_print2 - (1 if show_length else 0) i1 = n_rows - n_print2 - max_lines % 2 indices = np.concatenate([np.arange(0, i0 + 1), np.arange(i1 + 1, len(col))]) else: i0 = -1 indices = np.arange(len(col)) def format_col_str(idx): if multidims: # Prevents columns like Column(data=[[(1,)],[(2,)]], name='a') # with shape (n,1,...,1) from being printed as if there was # more than one element in a row if trivial_multidims: return format_func(col_format, col[(idx,) + multidim0]) else: left = format_func(col_format, col[(idx,) + multidim0]) right = format_func(col_format, col[(idx,) + multidim1]) return f'{left} .. {right}' else: return format_func(col_format, col[idx]) # Add formatted values if within bounds allowed by max_lines for idx in indices: if idx == i0: yield '...' else: try: yield format_col_str(idx) except ValueError: raise ValueError( 'Unable to parse format string "{}" for entry "{}" ' 'in column "{}"'.format(col_format, col[idx], col.info.name)) outs['show_length'] = show_length outs['n_header'] = n_header outs['i_centers'] = i_centers outs['i_dashes'] = i_dashes def _pformat_table(self, table, max_lines=None, max_width=None, show_name=True, show_unit=None, show_dtype=False, html=False, tableid=None, tableclass=None, align=None): """Return a list of lines for the formatted string representation of the table. Parameters ---------- max_lines : int or None Maximum number of rows to output max_width : int or None Maximum character width of output show_name : bool Include a header row for column names. Default is True. show_unit : bool Include a header row for unit. Default is to show a row for units only if one or more columns has a defined value for the unit. show_dtype : bool Include a header row for column dtypes. Default is False. html : bool Format the output as an HTML table. Default is False. tableid : str or None An ID tag for the table; only used if html is set. Default is "table{id}", where id is the unique integer id of the table object, id(table) tableclass : str or list of str or `None` CSS classes for the table; only used if html is set. Default is none align : str or list or tuple Left/right alignment of columns. Default is '>' (right) for all columns. Other allowed values are '<', '^', and '0=' for left, centered, and 0-padded, respectively. A list of strings can be provided for alignment of tables with multiple columns. Returns ------- rows : list Formatted table as a list of strings outs : dict Dict which is used to pass back additional values defined within the iterator. """ # "Print" all the values into temporary lists by column for subsequent # use and to determine the width max_lines, max_width = self._get_pprint_size(max_lines, max_width) cols = [] if show_unit is None: show_unit = any(col.info.unit for col in table.columns.values()) # Coerce align into a correctly-sized list of alignments (if possible) n_cols = len(table.columns) if align is None or isinstance(align, str): align = [align] * n_cols elif isinstance(align, (list, tuple)): if len(align) != n_cols: raise ValueError('got {} alignment values instead of ' 'the number of columns ({})' .format(len(align), n_cols)) else: raise TypeError('align keyword must be str or list or tuple (got {})' .format(type(align))) for align_, col in zip(align, table.columns.values()): lines, outs = self._pformat_col(col, max_lines, show_name=show_name, show_unit=show_unit, show_dtype=show_dtype, align=align_) if outs['show_length']: lines = lines[:-1] cols.append(lines) if not cols: return ['<No columns>'], {'show_length': False} # Use the values for the last column since they are all the same n_header = outs['n_header'] n_rows = len(cols[0]) outwidth = lambda cols: sum(len(c[0]) for c in cols) + len(cols) - 1 dots_col = ['...'] * n_rows middle = len(cols) // 2 while outwidth(cols) > max_width: if len(cols) == 1: break if len(cols) == 2: cols[1] = dots_col break if cols[middle] is dots_col: cols.pop(middle) middle = len(cols) // 2 cols[middle] = dots_col # Now "print" the (already-stringified) column values into a # row-oriented list. rows = [] if html: from astropy.utils.xml.writer import xml_escape if tableid is None: tableid = 'table{id}'.format(id=id(table)) if tableclass is not None: if isinstance(tableclass, list): tableclass = ' '.join(tableclass) rows.append('<table id="{tid}" class="{tcls}">'.format( tid=tableid, tcls=tableclass)) else: rows.append(f'<table id="{tableid}">') for i in range(n_rows): # _pformat_col output has a header line '----' which is not needed here if i == n_header - 1: continue td = 'th' if i < n_header else 'td' vals = ('<{}>{}</{}>'.format(td, xml_escape(col[i].strip()), td) for col in cols) row = ('<tr>' + ''.join(vals) + '</tr>') if i < n_header: row = ('<thead>' + row + '</thead>') rows.append(row) rows.append('</table>') else: for i in range(n_rows): row = ' '.join(col[i] for col in cols) rows.append(row) return rows, outs def _more_tabcol(self, tabcol, max_lines=None, max_width=None, show_name=True, show_unit=None, show_dtype=False): """Interactive "more" of a table or column. Parameters ---------- max_lines : int or None Maximum number of rows to output max_width : int or None Maximum character width of output show_name : bool Include a header row for column names. Default is True. show_unit : bool Include a header row for unit. Default is to show a row for units only if one or more columns has a defined value for the unit. show_dtype : bool Include a header row for column dtypes. Default is False. """ allowed_keys = 'f br<>qhpn' # Count the header lines n_header = 0 if show_name: n_header += 1 if show_unit: n_header += 1 if show_dtype: n_header += 1 if show_name or show_unit or show_dtype: n_header += 1 # Set up kwargs for pformat call. Only Table gets max_width. kwargs = dict(max_lines=-1, show_name=show_name, show_unit=show_unit, show_dtype=show_dtype) if hasattr(tabcol, 'columns'): # tabcol is a table kwargs['max_width'] = max_width # If max_lines is None (=> query screen size) then increase by 2. # This is because get_pprint_size leaves 6 extra lines so that in # ipython you normally see the last input line. max_lines1, max_width = self._get_pprint_size(max_lines, max_width) if max_lines is None: max_lines1 += 2 delta_lines = max_lines1 - n_header # Set up a function to get a single character on any platform inkey = Getch() i0 = 0 # First table/column row to show showlines = True while True: i1 = i0 + delta_lines # Last table/col row to show if showlines: # Don't always show the table (e.g. after help) try: os.system('cls' if os.name == 'nt' else 'clear') except Exception: pass # No worries if clear screen call fails lines = tabcol[i0:i1].pformat(**kwargs) colors = ('red' if i < n_header else 'default' for i in range(len(lines))) for color, line in zip(colors, lines): color_print(line, color) showlines = True print() print("-- f, <space>, b, r, p, n, <, >, q h (help) --", end=' ') # Get a valid key while True: try: key = inkey().lower() except Exception: print("\n") log.error('Console does not support getting a character' ' as required by more(). Use pprint() instead.') return if key in allowed_keys: break print(key) if key.lower() == 'q': break elif key == ' ' or key == 'f': i0 += delta_lines elif key == 'b': i0 = i0 - delta_lines elif key == 'r': pass elif key == '<': i0 = 0 elif key == '>': i0 = len(tabcol) elif key == 'p': i0 -= 1 elif key == 'n': i0 += 1 elif key == 'h': showlines = False print(""" Browsing keys: f, <space> : forward one page b : back one page r : refresh same page n : next row p : previous row < : go to beginning > : go to end q : quit browsing h : print this help""", end=' ') if i0 < 0: i0 = 0 if i0 >= len(tabcol) - delta_lines: i0 = len(tabcol) - delta_lines print("\n")