# Copyright 2014 Brett Slatkin, Pearson Education Inc.
#
# 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.
# Preamble to mimick book environment
import logging
from pprint import pprint
from sys import stdout as STDOUT
# Example 1
from urllib.parse import parse_qs
my_values = parse_qs('red=5&blue=0&green=',
keep_blank_values=True)
print(repr(my_values))
{'blue': ['0'], 'red': ['5'], 'green': ['']}
# Example 2
print('Red: ', my_values.get('red'))
print('Green: ', my_values.get('green'))
print('Opacity: ', my_values.get('opacity'))
Red: ['5'] Green: [''] Opacity: None
# Example 3
# For query string 'red=5&blue=0&green='
red = my_values.get('red', [''])[0] or 0
green = my_values.get('green', [''])[0] or 0
opacity = my_values.get('opacity', [''])[0] or 0
print('Red: %r' % red)
print('Green: %r' % green)
print('Opacity: %r' % opacity)
Red: '5' Green: 0 Opacity: 0
# Example 4
red = int(my_values.get('red', [''])[0] or 0)
green = int(my_values.get('green', [''])[0] or 0)
opacity = int(my_values.get('opacity', [''])[0] or 0)
print('Red: %r' % red)
print('Green: %r' % green)
print('Opacity: %r' % opacity)
Red: 5 Green: 0 Opacity: 0
# Example 5
red = my_values.get('red', [''])
red = int(red[0]) if red[0] else 0
green = my_values.get('green', [''])
green = int(green[0]) if green[0] else 0
opacity = my_values.get('opacity', [''])
opacity = int(opacity[0]) if opacity[0] else 0
print('Red: %r' % red)
print('Green: %r' % green)
print('Opacity: %r' % opacity)
Red: 5 Green: 0 Opacity: 0
# Example 6
green = my_values.get('green', [''])
if green[0]:
green = int(green[0])
else:
green = 0
print('Green: %r' % green)
Green: 0
# Example 7
def get_first_int(values, key, default=0):
found = values.get(key, [''])
if found[0]:
found = int(found[0])
else:
found = default
return found
# Example 8
green = get_first_int(my_values, 'green')
print('Green: %r' % green)
Green: 0