[MRG + 1] Add suppress_warnings flag (#155)

* Add suppress_warnings flag

* Add --quiet flag to cli (to suppress warnings)

* Remove TODO and update comment

camelot/cli.py

@@ -38,6 +38,7 @@ pass_config = click.make_pass_decorator(Config)
               ' font size. Useful to detect super/subscripts.')
 @click.option('-M', '--margins', nargs=3, default=(1.0, 0.5, 0.1),
               help='PDFMiner char_margin, line_margin and word_margin.')
+@click.option('-q', '--quiet', is_flag=True, help='Suppress warnings.')
 @click.pass_context
 def cli(ctx, *args, **kwargs):
     """Camelot: PDF Table Extraction for Humans"""
@@ -89,6 +90,7 @@ def lattice(c, *args, **kwargs):
     output = conf.pop('output')
     f = conf.pop('format')
     compress = conf.pop('zip')
+    suppress_warnings = conf.pop('quiet')
     plot_type = kwargs.pop('plot_type')
     filepath = kwargs.pop('filepath')
     kwargs.update(conf)
@@ -99,7 +101,8 @@ def lattice(c, *args, **kwargs):
     kwargs['copy_text'] = None if not copy_text else copy_text
     kwargs['shift_text'] = list(kwargs['shift_text'])
 
-    tables = read_pdf(filepath, pages=pages, flavor='lattice', **kwargs)
+    tables = read_pdf(filepath, pages=pages, flavor='lattice',
+                      suppress_warnings=suppress_warnings, **kwargs)
     click.echo('Found {} tables'.format(tables.n))
     if plot_type is not None:
         for table in tables:
@@ -134,6 +137,7 @@ def stream(c, *args, **kwargs):
     output = conf.pop('output')
     f = conf.pop('format')
     compress = conf.pop('zip')
+    suppress_warnings = conf.pop('quiet')
     plot_type = kwargs.pop('plot_type')
     filepath = kwargs.pop('filepath')
     kwargs.update(conf)
@@ -143,7 +147,8 @@ def stream(c, *args, **kwargs):
     columns = list(kwargs['columns'])
     kwargs['columns'] = None if not columns else columns
 
-    tables = read_pdf(filepath, pages=pages, flavor='stream', **kwargs)
+    tables = read_pdf(filepath, pages=pages, flavor='stream',
+                      suppress_warnings=suppress_warnings, **kwargs)
     click.echo('Found {} tables'.format(tables.n))
     if plot_type is not None:
         for table in tables:

camelot/io.py

@@ -1,10 +1,12 @@
 # -*- coding: utf-8 -*-
+import warnings
 
 from .handlers import PDFHandler
 from .utils import validate_input, remove_extra
 
 
-def read_pdf(filepath, pages='1', flavor='lattice', **kwargs):
+def read_pdf(filepath, pages='1', flavor='lattice', suppress_warnings=False,
+             **kwargs):
     """Read PDF and return extracted tables.
 
     Note: kwargs annotated with ^ can only be used with flavor='stream'
@@ -20,6 +22,8 @@ def read_pdf(filepath, pages='1', flavor='lattice', **kwargs):
     flavor : str (default: 'lattice')
         The parsing method to use ('lattice' or 'stream').
         Lattice is used by default.
+    suppress_warnings : bool, optional (default: False)
+        Prevent warnings from being emitted by Camelot.
     table_area : list, optional (default: None)
         List of table area strings of the form x1,y1,x2,y2
         where (x1, y1) -> left-top and (x2, y2) -> right-bottom
@@ -85,8 +89,12 @@ def read_pdf(filepath, pages='1', flavor='lattice', **kwargs):
         raise NotImplementedError("Unknown flavor specified."
                                   " Use either 'lattice' or 'stream'")
 
-    validate_input(kwargs, flavor=flavor)
-    p = PDFHandler(filepath, pages)
-    kwargs = remove_extra(kwargs, flavor=flavor)
-    tables = p.parse(flavor=flavor, **kwargs)
-    return tables
+    with warnings.catch_warnings():
+        if suppress_warnings:
+            warnings.simplefilter("ignore")
+
+        validate_input(kwargs, flavor=flavor)
+        p = PDFHandler(filepath, pages)
+        kwargs = remove_extra(kwargs, flavor=flavor)
+        tables = p.parse(flavor=flavor, **kwargs)
+        return tables