effectivepython/example_code/item_30.py at master · sharc007/effectivepython · GitHub

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#!/usr/bin/env PYTHONHASHSEED=1234 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.

# Reproduce book environment

import random

random.seed(1234)

import logging

from pprint import pprint

from sys import stdout as STDOUT

# Write all output to a temporary directory

import atexit

import gc

import io

import os

import tempfile

TEST_DIR = tempfile.TemporaryDirectory()

atexit.register(TEST_DIR.cleanup)

# Make sure Windows processes exit cleanly

OLD_CWD = os.getcwd()

atexit.register(lambda: os.chdir(OLD_CWD))

os.chdir(TEST_DIR.name)

def close_open_files():

everything = gc.get_objects()

for obj in everything:

if isinstance(obj, io.IOBase):

obj.close()

atexit.register(close_open_files)

# Example 1

def index_words(text):

result = []

if text:

result.append(0)

for index, letter in enumerate(text):

if letter == ' ':

result.append(index + 1)

return result

# Example 2

address = 'Four score and seven years ago...'

address = 'Four score and seven years ago our fathers brought forth on this continent a new nation, conceived in liberty, and dedicated to the proposition that all men are created equal.'

result = index_words(address)

print(result[:10])

# Example 3

def index_words_iter(text):

if text:

yield 0

for index, letter in enumerate(text):

if letter == ' ':

yield index + 1

# Example 4

it = index_words_iter(address)

print(next(it))

# Example 5

result = list(index_words_iter(address))

print(result[:10])

# Example 6

def index_file(handle):

offset = 0

for line in handle:

if line:

yield offset

for letter in line:

offset += 1

if letter == ' ':

yield offset

# Example 7

address_lines = """Four score and seven years

ago our fathers brought forth on this

continent a new nation, conceived in liberty,

and dedicated to the proposition that all men

are created equal."""

with open('address.txt', 'w') as f:

f.write(address_lines)

import itertools

with open('address.txt', 'r') as f:

it = index_file(f)

results = itertools.islice(it, 0, 10)

print(list(results))

effectivepython/example_code/item_30.py at master · sharc007/effectivepython · GitHub

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