Files
deb-python-taskflow/taskflow/types/table.py
Joshua Harlow 42a665d06f Use platform neutral line separator(s)
To at least try to support things like windows it's better
if we can make an attempt to use the platform neutral
characters for line separator(s) where appropriate.

Change-Id: Icc533ed4d4c94f461b7f19600b74146221f17b18
2015-01-12 20:33:51 -08:00

131 lines
5.3 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (C) 2014 Yahoo! Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import itertools
import os
import six
class PleasantTable(object):
"""A tiny pretty printing table (like prettytable/tabulate but smaller).
Creates simply formatted tables (with no special sauce)::
>>> from taskflow.types import table
>>> tbl = table.PleasantTable(['Name', 'City', 'State', 'Country'])
>>> tbl.add_row(["Josh", "San Jose", "CA", "USA"])
>>> print(tbl.pformat())
+------+----------+-------+---------+
Name | City | State | Country
+------+----------+-------+---------+
Josh | San Jose | CA | USA
+------+----------+-------+---------+
"""
COLUMN_STARTING_CHAR = ' '
COLUMN_ENDING_CHAR = ''
COLUMN_SEPARATOR_CHAR = '|'
HEADER_FOOTER_JOINING_CHAR = '+'
HEADER_FOOTER_CHAR = '-'
LINE_SEP = os.linesep
@staticmethod
def _center_text(text, max_len, fill=' '):
return '{0:{fill}{align}{size}}'.format(text, fill=fill,
align="^", size=max_len)
@classmethod
def _size_selector(cls, possible_sizes):
# The number two is used so that the edges of a column have spaces
# around them (instead of being right next to a column separator).
try:
return max(x + 2 for x in possible_sizes)
except ValueError:
return 0
def __init__(self, columns):
if len(columns) == 0:
raise ValueError("Column count must be greater than zero")
self._columns = [column.strip() for column in columns]
self._rows = []
def add_row(self, row):
if len(row) != len(self._columns):
raise ValueError("Row must have %s columns instead of"
" %s columns" % (len(self._columns), len(row)))
self._rows.append([six.text_type(column) for column in row])
def pformat(self):
# Figure out the maximum column sizes...
column_count = len(self._columns)
column_sizes = [0] * column_count
headers = []
for i, column in enumerate(self._columns):
possible_sizes_iter = itertools.chain(
[len(column)], (len(row[i]) for row in self._rows))
column_sizes[i] = self._size_selector(possible_sizes_iter)
headers.append(self._center_text(column, column_sizes[i]))
# Build the header and footer prefix/postfix.
header_footer_buf = six.StringIO()
header_footer_buf.write(self.HEADER_FOOTER_JOINING_CHAR)
for i, header in enumerate(headers):
header_footer_buf.write(self.HEADER_FOOTER_CHAR * len(header))
if i + 1 != column_count:
header_footer_buf.write(self.HEADER_FOOTER_JOINING_CHAR)
header_footer_buf.write(self.HEADER_FOOTER_JOINING_CHAR)
# Build the main header.
content_buf = six.StringIO()
content_buf.write(header_footer_buf.getvalue())
content_buf.write(self.LINE_SEP)
content_buf.write(self.COLUMN_STARTING_CHAR)
for i, header in enumerate(headers):
if i + 1 == column_count:
if self.COLUMN_ENDING_CHAR:
content_buf.write(headers[i])
content_buf.write(self.COLUMN_ENDING_CHAR)
else:
content_buf.write(headers[i].rstrip())
else:
content_buf.write(headers[i])
content_buf.write(self.COLUMN_SEPARATOR_CHAR)
content_buf.write(self.LINE_SEP)
content_buf.write(header_footer_buf.getvalue())
# Build the main content.
row_count = len(self._rows)
if row_count:
content_buf.write(self.LINE_SEP)
for i, row in enumerate(self._rows):
pieces = []
for j, column in enumerate(row):
pieces.append(self._center_text(column, column_sizes[j]))
if j + 1 != column_count:
pieces.append(self.COLUMN_SEPARATOR_CHAR)
blob = ''.join(pieces)
if self.COLUMN_ENDING_CHAR:
content_buf.write(self.COLUMN_STARTING_CHAR)
content_buf.write(blob)
content_buf.write(self.COLUMN_ENDING_CHAR)
else:
blob = blob.rstrip()
if blob:
content_buf.write(self.COLUMN_STARTING_CHAR)
content_buf.write(blob)
if i + 1 != row_count:
content_buf.write(self.LINE_SEP)
content_buf.write(self.LINE_SEP)
content_buf.write(header_footer_buf.getvalue())
return content_buf.getvalue()