# 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
def log(message, values):
if not values:
print(message)
else:
values_str = ', '.join(str(x) for x in values)
print('%s: %s' % (message, values_str))
log('My numbers are', [1, 2])
log('Hi there', [])
My numbers are: 1, 2 Hi there
# Example 2
def log(message, *values): # The only difference
if not values:
print(message)
else:
values_str = ', '.join(str(x) for x in values)
print('%s: %s' % (message, values_str))
log('My numbers are', 1, 2)
log('Hi there') # Much better
My numbers are: 1, 2 Hi there
# Example 3
favorites = [7, 33, 99]
log('Favorite colors', *favorites)
Favorite colors: 7, 33, 99
# Example 4
def my_generator():
for i in range(10):
yield i
def my_func(*args):
print(args)
it = my_generator()
my_func(*it)
(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
# Example 5
def log(sequence, message, *values):
if not values:
print('%s: %s' % (sequence, message))
else:
values_str = ', '.join(str(x) for x in values)
print('%s: %s: %s' % (sequence, message, values_str))
log(1, 'Favorites', 7, 33) # New usage is OK
log('Favorite numbers', 7, 33) # Old usage breaks
1: Favorites: 7, 33 Favorite numbers: 7: 33