effectivepython/example_code/item_20.py at master · AISTLAB/effectivepython · GitHub

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#!/usr/bin/env python3

# 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 time import sleep

from datetime import datetime

def log(message, when=datetime.now()):

print('%s: %s' % (when, message))

log('Hi there!')

sleep(0.1)

log('Hi again!')

# Example 2

def log(message, when=None):

"""Log a message with a timestamp.

Args:

message: Message to print.

when: datetime of when the message occurred.

Defaults to the present time.

"""

when = datetime.now() if when is None else when

print('%s: %s' % (when, message))

# Example 3

log('Hi there!')

sleep(0.1)

log('Hi again!')

# Example 4

import json

def decode(data, default={}):

try:

return json.loads(data)

except ValueError:

return default

# Example 5

foo = decode('bad data')

foo['stuff'] = 5

bar = decode('also bad')

bar['meep'] = 1

print('Foo:', foo)

print('Bar:', bar)

# Example 6

assert foo is bar

# Example 7

def decode(data, default=None):

"""Load JSON data from a string.

Args:

data: JSON data to decode.

default: Value to return if decoding fails.

Defaults to an empty dictionary.

"""

if default is None:

default = {}