effectivepython/example_code/item_04.py at master · sharc007/effectivepython · GitHub

History

executable file

311 lines (223 loc) · 6.06 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

#!/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

a = 0b10111011

b = 0xc5f

print('Binary is %d, hex is %d' % (a, b))

# Example 2

key = 'my_var'

value = 1.234

formatted = '%-10s = %.2f' % (key, value)

print(formatted)

# Example 3

try:

reordered_tuple = '%-10s = %.2f' % (value, key)

except:

logging.exception('Expected')

else:

assert False

# Example 4

try:

reordered_string = '%.2f = %-10s' % (key, value)

except:

logging.exception('Expected')

else:

assert False

# Example 5

pantry = [

('avocados', 1.25),

('bananas', 2.5),

('cherries', 15),

]

for i, (item, count) in enumerate(pantry):

print('#%d: %-10s = %.2f' % (i, item, count))

# Example 6

for i, (item, count) in enumerate(pantry):

print('#%d: %-10s = %d' % (

i + 1,

item.title(),

round(count)))

# Example 7

template = '%s loves food. See %s cook.'

name = 'Max'

formatted = template % (name, name)

print(formatted)

# Example 8

name = 'brad'

formatted = template % (name.title(), name.title())

print(formatted)

# Example 9

key = 'my_var'

value = 1.234

old_way = '%-10s = %.2f' % (key, value)

new_way = '%(key)-10s = %(value).2f' % {

'key': key, 'value': value} # Original

reordered = '%(key)-10s = %(value).2f' % {

'value': value, 'key': key} # Swapped

assert old_way == new_way == reordered

# Example 10

name = 'Max'

template = '%s loves food. See %s cook.'

before = template % (name, name) # Tuple

template = '%(name)s loves food. See %(name)s cook.'

after = template % {'name': name} # Dictionary

assert before == after

# Example 11

for i, (item, count) in enumerate(pantry):

before = '#%d: %-10s = %d' % (

i + 1,

item.title(),

round(count))

after = '#%(loop)d: %(item)-10s = %(count)d' % {

'loop': i + 1,

'item': item.title(),

'count': round(count),

}

assert before == after

# Example 12

soup = 'lentil'

formatted = 'Today\'s soup is %(soup)s.' % {'soup': soup}

print(formatted)

# Example 13

menu = {

'soup': 'lentil',

'oyster': 'kumamoto',

'special': 'schnitzel',

}

template = ('Today\'s soup is %(soup)s, '

'buy one get two %(oyster)s oysters, '

'and our special entrée is %(special)s.')

formatted = template % menu

print(formatted)

# Example 14

a = 1234.5678

formatted = format(a, ',.2f')

print(formatted)

b = 'my string'

formatted = format(b, '^20s')

print('*', formatted, '*')

# Example 15

key = 'my_var'

value = 1.234

formatted = '{} = {}'.format(key, value)

print(formatted)

# Example 16

formatted = '{:<10} = {:.2f}'.format(key, value)

print(formatted)

# Example 17

print('%.2f%%' % 12.5)

print('{} replaces {{}}'.format(1.23))

# Example 18

formatted = '{1} = {0}'.format(key, value)

print(formatted)

# Example 19

formatted = '{0} loves food. See {0} cook.'.format(name)

print(formatted)

# Example 20

for i, (item, count) in enumerate(pantry):

old_style = '#%d: %-10s = %d' % (

i + 1,

item.title(),

round(count))

new_style = '#{}: {:<10s} = {}'.format(

i + 1,

item.title(),

round(count))

assert old_style == new_style

# Example 21

formatted = 'First letter is {menu[oyster][0]!r}'.format(

menu=menu)

print(formatted)

# Example 22

old_template = (

'Today\'s soup is %(soup)s, '

'buy one get two %(oyster)s oysters, '

'and our special entrée is %(special)s.')

old_formatted = old_template % {

'soup': 'lentil',

'oyster': 'kumamoto',

'special': 'schnitzel',

}

new_template = (

'Today\'s soup is {soup}, '

'buy one get two {oyster} oysters, '

'and our special entrée is {special}.')

new_formatted = new_template.format(

soup='lentil',

oyster='kumamoto',

special='schnitzel',

)

assert old_formatted == new_formatted

# Example 23

key = 'my_var'

value = 1.234

formatted = f'{key} = {value}'

print(formatted)

# Example 24

formatted = f'{key!r:<10} = {value:.2f}'

print(formatted)

# Example 25

f_string = f'{key:<10} = {value:.2f}'

c_tuple = '%-10s = %.2f' % (key, value)

str_args = '{:<10} = {:.2f}'.format(key, value)

str_kw = '{key:<10} = {value:.2f}'.format(key=key, value=value)

c_dict = '%(key)-10s = %(value).2f' % {'key': key, 'value': value}

assert c_tuple == c_dict == f_string

assert str_args == str_kw == f_string

# Example 26

for i, (item, count) in enumerate(pantry):

old_style = '#%d: %-10s = %d' % (

i + 1,

item.title(),

round(count))

new_style = '#{}: {:<10s} = {}'.format(

i + 1,

item.title(),

round(count))

f_string = f'#{i+1}: {item.title():<10s} = {round(count)}'

assert old_style == new_style == f_string

# Example 27

for i, (item, count) in enumerate(pantry):

print(f'#{i+1}: '

f'{item.title():<10s} = '

f'{round(count)}')

# Example 28

places = 3

number = 1.23456

print(f'My number is {number:.{places}f}')

effectivepython/example_code/item_04.py at master · sharc007/effectivepython · GitHub

Expand file tree

Breadcrumbs

item_04.py

Latest commit

History

Breadcrumbs

item_04.py

File metadata and controls