513 lines
19 KiB
Python
513 lines
19 KiB
Python
from __future__ import division
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import os
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import sys
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import copy
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import types
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import logging
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import copy_reg
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import warnings
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import subprocess
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import numpy as np
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import pandas as pd
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from .core import Table, Geometry
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from .image_processing import (adaptive_threshold, find_lines, find_table_contours,
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find_table_joints)
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from .utils import (scale_image, scale_pdf, segments_in_bbox, text_in_bbox,
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merge_close_values, get_table_index, compute_accuracy, count_empty,
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get_text_objects, get_page_layout, encode_)
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__all__ = ['Stream', 'Lattice']
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logger = logging.getLogger('app_logger')
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def _reduce_method(m):
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if m.im_self is None:
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return getattr, (m.im_class, m.im_func.func_name)
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else:
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return getattr, (m.im_self, m.im_func.func_name)
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copy_reg.pickle(types.MethodType, _reduce_method)
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class BaseParser(object):
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# init objects
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# no tables condition
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# convert pdf to image - lattice
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# image processing - lattice
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# user given table area condition
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# scale image components to pdf components - lattice
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# compute cols and rows for each table
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# create table for each table
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def _generate_layout(self, filename):
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self.filename = filename
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self.layout, self.dimensions = get_page_layout(
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self.filename,
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char_margin=self.char_margin,
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line_margin=self.line_margin,
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word_margin=self.word_margin)
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self.horizontal_text = get_text_objects(self.layout, ltype="lh")
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self.vertical_text = get_text_objects(self.layout, ltype="lv")
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self.pdf_width, self.pdf_height = self.dimensions
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self.basename, __ = os.path.splitext(self.filename)
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self.g = Geometry()
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class Stream(BaseParser):
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"""
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"""
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def __init__(self, table_area=None, columns=None, ytol=2, mtol=0,
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margins=(1.0, 0.5, 0.1), split_text=False, flag_size=True,
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debug=False):
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self.table_area = table_area
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self.columns = columns
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self._validate_columns()
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self.ytol = ytol
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self.mtol = mtol
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self.char_margin, self.line_margin, self.word_margin = margins
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self.split_text = split_text
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self.flag_size = flag_size
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self.debug = debug
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def _validate_columns(self):
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if self.table_area is not None and self.columns is not None:
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if len(self.table_area) != len(self.columns):
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raise ValueError("Length of table_area and columns"
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" should be equal.")
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@staticmethod
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def _text_bbox(t_bbox):
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xmin = min([t.x0 for direction in t_bbox for t in t_bbox[direction]])
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ymin = min([t.y0 for direction in t_bbox for t in t_bbox[direction]])
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xmax = max([t.x1 for direction in t_bbox for t in t_bbox[direction]])
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ymax = max([t.y1 for direction in t_bbox for t in t_bbox[direction]])
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text_bbox = (xmin, ymin, xmax, ymax)
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return text_bbox
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@staticmethod
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def _group_rows(text, ytol=2):
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row_y = 0
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rows = []
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temp = []
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for t in text:
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# is checking for upright necessary?
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# if t.get_text().strip() and all([obj.upright for obj in t._objs if
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# type(obj) is LTChar]):
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if t.get_text().strip():
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if not np.isclose(row_y, t.y0, atol=ytol):
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rows.append(sorted(temp, key=lambda t: t.x0))
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temp = []
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row_y = t.y0
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temp.append(t)
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rows.append(sorted(temp, key=lambda t: t.x0))
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__ = rows.pop(0) # hacky
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return rows
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@staticmethod
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def _merge_columns(l, mtol=0):
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merged = []
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for higher in l:
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if not merged:
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merged.append(higher)
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else:
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lower = merged[-1]
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if mtol >= 0:
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if (higher[0] <= lower[1] or
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np.isclose(higher[0], lower[1], atol=mtol)):
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upper_bound = max(lower[1], higher[1])
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lower_bound = min(lower[0], higher[0])
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merged[-1] = (lower_bound, upper_bound)
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else:
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merged.append(higher)
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elif mtol < 0:
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if higher[0] <= lower[1]:
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if np.isclose(higher[0], lower[1], atol=abs(mtol)):
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merged.append(higher)
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else:
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upper_bound = max(lower[1], higher[1])
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lower_bound = min(lower[0], higher[0])
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merged[-1] = (lower_bound, upper_bound)
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else:
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merged.append(higher)
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return merged
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@staticmethod
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def _join_rows(rows_grouped, text_y_max, text_y_min):
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row_mids = [sum([(t.y0 + t.y1) / 2 for t in r]) / len(r)
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if len(r) > 0 else 0 for r in rows_grouped]
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rows = [(row_mids[i] + row_mids[i - 1]) / 2 for i in range(1, len(row_mids))]
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rows.insert(0, text_y_max)
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rows.append(text_y_min)
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rows = [(rows[i], rows[i + 1])
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for i in range(0, len(rows) - 1)]
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return rows
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@staticmethod
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def _add_columns(cols, text, ytol):
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if text:
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text = Stream._group_rows(text, ytol=ytol)
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elements = [len(r) for r in text]
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new_cols = [(t.x0, t.x1)
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for r in text if len(r) == max(elements) for t in r]
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cols.extend(Stream._merge_columns(sorted(new_cols)))
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return cols
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@staticmethod
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def _join_columns(cols, text_x_min, text_x_max):
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cols = sorted(cols)
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cols = [(cols[i][0] + cols[i - 1][1]) / 2 for i in range(1, len(cols))]
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cols.insert(0, text_x_min)
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cols.append(text_x_max)
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cols = [(cols[i], cols[i + 1])
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for i in range(0, len(cols) - 1)]
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return cols
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def _generate_table_bbox(self):
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if self.table_area is not None:
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table_bbox = {}
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for area in self.table_area:
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x1, y1, x2, y2 = area.split(",")
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x1 = float(x1)
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y1 = float(y1)
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x2 = float(x2)
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y2 = float(y2)
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table_bbox[(x1, y2, x2, y1)] = None
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else:
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table_bbox = {(0, 0, self.pdf_width, self.pdf_height): None}
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self.table_bbox = table_bbox
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def _generate_columns_and_rows(self, table_idx, tk):
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# select elements which lie within table_bbox
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t_bbox = {}
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t_bbox['horizontal'] = text_in_bbox(tk, self.horizontal_text)
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t_bbox['vertical'] = text_in_bbox(tk, self.vertical_text)
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self.t_bbox = t_bbox
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for direction in self.t_bbox:
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self.t_bbox[direction].sort(key=lambda x: (-x.y0, x.x0))
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text_x_min, text_y_min, text_x_max, text_y_max = self._text_bbox(self.t_bbox)
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rows_grouped = self._group_rows(self.t_bbox['horizontal'], ytol=self.ytol)
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rows = self._join_rows(rows_grouped, text_y_max, text_y_min)
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elements = [len(r) for r in rows_grouped]
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if self.columns is not None and self.columns[table_idx] != "":
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# user has to input boundary columns too
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# take (0, pdf_width) by default
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# similar to else condition
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# len can't be 1
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cols = self.columns[table_idx].split(',')
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cols = [float(c) for c in cols]
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cols.insert(0, text_x_min)
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cols.append(text_x_max)
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cols = [(cols[i], cols[i + 1]) for i in range(0, len(cols) - 1)]
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else:
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ncols = max(set(elements), key=elements.count)
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if ncols == 1:
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# no tables condition
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warnings.warn("No tables found on {}".format(
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os.path.basename(self.basename)))
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cols = [(t.x0, t.x1)
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for r in rows_grouped if len(r) == ncols for t in r]
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cols = self._merge_columns(sorted(cols), mtol=self.mtol)
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inner_text = []
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for i in range(1, len(cols)):
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left = cols[i - 1][1]
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right = cols[i][0]
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inner_text.extend([t for direction in self.t_bbox
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for t in self.t_bbox[direction]
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if t.x0 > left and t.x1 < right])
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outer_text = [t for direction in self.t_bbox
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for t in self.t_bbox[direction]
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if t.x0 > cols[-1][1] or t.x1 < cols[0][0]]
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inner_text.extend(outer_text)
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cols = self._add_columns(cols, inner_text, self.ytol)
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cols = self._join_columns(cols, text_x_min, text_x_max)
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return cols, rows
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def _generate_table(self, table_idx, cols, rows):
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table = Table(cols, rows)
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table = table.set_all_edges()
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pos_errors = []
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for direction in self.t_bbox:
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for t in self.t_bbox[direction]:
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indices, error = get_table_index(
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table, t, direction, split_text=self.split_text,
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flag_size=self.flag_size)
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if indices[:2] != (-1, -1):
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pos_errors.append(error)
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for r_idx, c_idx, text in indices:
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table.cells[r_idx][c_idx].add_text(text)
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accuracy = compute_accuracy([[100, pos_errors]])
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data = table.data
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data = encode_(data)
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table.df = pd.DataFrame(data)
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table.shape = table.df.shape
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whitespace, __, __ = count_empty(data)
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table.accuracy = accuracy
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table.whitespace = whitespace
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table.order = table_idx + 1
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table.page = int(os.path.basename(self.basename).replace('page-', ''))
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return table
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def extract_tables(self, filename):
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"""
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Parameters
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----------
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filename
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Returns
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-------
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"""
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logger.info('Processing {}'.format(os.path.basename(filename)))
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self._generate_layout(filename)
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if not self.horizontal_text:
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warnings.warn("No tables found on {}".format(
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os.path.basename(self.basename)))
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return [], self.g
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if self.debug:
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text = []
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text.extend([(t.x0, t.y0, t.x1, t.y1) for t in self.horizontal_text])
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text.extend([(t.x0, t.y0, t.x1, t.y1) for t in self.vertical_text])
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self.g.text = text
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self._generate_table_bbox()
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_tables = []
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# sort tables based on y-coord
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for table_idx, tk in enumerate(sorted(self.table_bbox.keys(),
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key=lambda x: x[1], reverse=True)):
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cols, rows = self._generate_columns_and_rows(table_idx, tk)
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table = self._generate_table(table_idx, cols, rows)
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_tables.append(table)
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return _tables, self.g
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class Lattice(BaseParser):
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"""
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"""
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def __init__(self, table_area=None, fill=None, mtol=2, jtol=2,
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blocksize=15, threshold_constant=-2, scale=15, iterations=0,
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invert=False, margins=(1.0, 0.5, 0.1), split_text=False,
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flag_size=True, shift_text=['l', 't'], debug=None):
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self.table_area = table_area
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self.fill = fill
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self.mtol = mtol
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self.jtol = jtol
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self.blocksize = blocksize
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self.threshold_constant = threshold_constant
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self.scale = scale
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self.iterations = iterations
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self.invert = invert
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self.char_margin, self.line_margin, self.word_margin = margins
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self.split_text = split_text
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self.flag_size = flag_size
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self.shift_text = shift_text
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self.debug = debug
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@staticmethod
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def _reduce_index(t, idx, shift_text):
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indices = []
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for r_idx, c_idx, text in idx:
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for d in shift_text:
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if d == 'l':
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if t.cells[r_idx][c_idx].spanning_h:
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while not t.cells[r_idx][c_idx].left:
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c_idx -= 1
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if d == 'r':
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if t.cells[r_idx][c_idx].spanning_h:
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while not t.cells[r_idx][c_idx].right:
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c_idx += 1
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if d == 't':
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if t.cells[r_idx][c_idx].spanning_v:
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while not t.cells[r_idx][c_idx].top:
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r_idx -= 1
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if d == 'b':
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if t.cells[r_idx][c_idx].spanning_v:
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while not t.cells[r_idx][c_idx].bottom:
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r_idx += 1
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indices.append((r_idx, c_idx, text))
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return indices
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@staticmethod
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def _fill_spanning(t, fill=None):
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for f in fill:
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if f == "h":
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for i in range(len(t.cells)):
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for j in range(len(t.cells[i])):
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if t.cells[i][j].get_text().strip() == '':
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if t.cells[i][j].spanning_h and not t.cells[i][j].left:
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t.cells[i][j].add_text(t.cells[i][j - 1].get_text())
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elif f == "v":
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for i in range(len(t.cells)):
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for j in range(len(t.cells[i])):
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if t.cells[i][j].get_text().strip() == '':
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if t.cells[i][j].spanning_v and not t.cells[i][j].top:
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t.cells[i][j].add_text(t.cells[i - 1][j].get_text())
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return t
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def _generate_image(self):
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self.imagename = ''.join([self.basename, '.png'])
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gs_call = [
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"-q", "-sDEVICE=png16m", "-o", self.imagename, "-r600", self.filename
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]
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if "ghostscript" in subprocess.check_output(["gs", "-version"]).lower():
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gs_call.insert(0, "gs")
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else:
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gs_call.insert(0, "gsc")
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subprocess.call(gs_call, stdout=open(os.devnull, 'w'),
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stderr=subprocess.STDOUT)
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def _generate_table_bbox(self):
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self.image, self.threshold = adaptive_threshold(self.imagename, invert=self.invert,
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blocksize=self.blocksize, c=self.threshold_constant)
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image_width = self.image.shape[1]
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image_height = self.image.shape[0]
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image_width_scaler = image_width / float(self.pdf_width)
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image_height_scaler = image_height / float(self.pdf_height)
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pdf_width_scaler = self.pdf_width / float(image_width)
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pdf_height_scaler = self.pdf_height / float(image_height)
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image_scalers = (image_width_scaler, image_height_scaler, self.pdf_height)
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pdf_scalers = (pdf_width_scaler, pdf_height_scaler, image_height)
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vertical_mask, vertical_segments = find_lines(self.threshold,
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direction='vertical', scale=self.scale, iterations=self.iterations)
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horizontal_mask, horizontal_segments = find_lines(self.threshold,
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direction='horizontal', scale=self.scale, iterations=self.iterations)
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if self.table_area is not None:
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areas = []
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for area in self.table_area:
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x1, y1, x2, y2 = area.split(",")
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x1 = float(x1)
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y1 = float(y1)
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x2 = float(x2)
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y2 = float(y2)
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x1, y1, x2, y2 = scale_pdf((x1, y1, x2, y2), image_scalers)
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areas.append((x1, y1, abs(x2 - x1), abs(y2 - y1)))
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table_bbox = find_table_joints(areas, vertical_mask, horizontal_mask)
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else:
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contours = find_table_contours(vertical_mask, horizontal_mask)
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table_bbox = find_table_joints(contours, vertical_mask, horizontal_mask)
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self.table_bbox_unscaled = copy.deepcopy(table_bbox)
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self.table_bbox, self.vertical_segments, self.horizontal_segments = scale_image(
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table_bbox, vertical_segments, horizontal_segments, pdf_scalers)
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def _generate_columns_and_rows(self, table_idx, tk):
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# select elements which lie within table_bbox
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t_bbox = {}
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v_s, h_s = segments_in_bbox(
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tk, self.vertical_segments, self.horizontal_segments)
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t_bbox['horizontal'] = text_in_bbox(tk, self.horizontal_text)
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t_bbox['vertical'] = text_in_bbox(tk, self.vertical_text)
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self.t_bbox = t_bbox
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for direction in t_bbox:
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t_bbox[direction].sort(key=lambda x: (-x.y0, x.x0))
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cols, rows = zip(*self.table_bbox[tk])
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cols, rows = list(cols), list(rows)
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cols.extend([tk[0], tk[2]])
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rows.extend([tk[1], tk[3]])
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# sort horizontal and vertical segments
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cols = merge_close_values(sorted(cols), mtol=self.mtol)
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rows = merge_close_values(sorted(rows, reverse=True), mtol=self.mtol)
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# make grid using x and y coord of shortlisted rows and cols
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cols = [(cols[i], cols[i + 1])
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for i in range(0, len(cols) - 1)]
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rows = [(rows[i], rows[i + 1])
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for i in range(0, len(rows) - 1)]
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return cols, rows, v_s, h_s
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def _generate_table(self, table_idx, cols, rows, v_s, h_s):
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table = Table(cols, rows)
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# set table edges to True using ver+hor lines
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table = table.set_edges(v_s, h_s, jtol=self.jtol)
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# set spanning cells to True
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table = table.set_spanning()
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# set table border edges to True
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table = table.set_border_edges()
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pos_errors = []
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for direction in self.t_bbox:
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for t in self.t_bbox[direction]:
|
|
indices, error = get_table_index(
|
|
table, t, direction, split_text=self.split_text,
|
|
flag_size=self.flag_size)
|
|
if indices[:2] != (-1, -1):
|
|
pos_errors.append(error)
|
|
indices = Lattice._reduce_index(table, indices, shift_text=self.shift_text)
|
|
for r_idx, c_idx, text in indices:
|
|
table.cells[r_idx][c_idx].add_text(text)
|
|
accuracy = compute_accuracy([[100, pos_errors]])
|
|
|
|
if self.fill is not None:
|
|
table = Lattice._fill_spanning(table, fill=self.fill)
|
|
|
|
data = table.data
|
|
data = encode_(data)
|
|
table.df = pd.DataFrame(data)
|
|
table.shape = table.df.shape
|
|
|
|
whitespace, __, __ = count_empty(data)
|
|
table.accuracy = accuracy
|
|
table.whitespace = whitespace
|
|
table.order = table_idx + 1
|
|
table.page = int(os.path.basename(self.basename).replace('page-', ''))
|
|
|
|
return table
|
|
|
|
def extract_tables(self, filename):
|
|
"""
|
|
|
|
Parameters
|
|
----------
|
|
filename
|
|
|
|
Returns
|
|
-------
|
|
|
|
"""
|
|
logger.info('Processing {}'.format(os.path.basename(filename)))
|
|
self._generate_layout(filename)
|
|
|
|
if not self.horizontal_text:
|
|
warnings.warn("No tables found on {}".format(
|
|
os.path.basename(self.basename)))
|
|
return [], self.g
|
|
|
|
self._generate_image()
|
|
self._generate_table_bbox()
|
|
|
|
if self.debug:
|
|
self.g.images = (self.image, self.table_bbox_unscaled)
|
|
self.g.segments = (self.vertical_segments, self.horizontal_segments)
|
|
|
|
_tables = []
|
|
# sort tables based on y-coord
|
|
for table_idx, tk in enumerate(sorted(self.table_bbox.keys(),
|
|
key=lambda x: x[1], reverse=True)):
|
|
cols, rows, v_s, h_s = self._generate_columns_and_rows(table_idx, tk)
|
|
table = self._generate_table(table_idx, cols, rows, v_s, h_s)
|
|
_tables.append(table)
|
|
|
|
if self.debug:
|
|
self.g.tables = _tables
|
|
|
|
return _tables, self.g |