cpython/Lib/code.py at tkinter_docs · native-api/cpython · GitHub

Repository navigation

History

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

312

313

314

315

"""Utilities needed to emulate Python's interactive interpreter.

"""

# Inspired by similar code by Jeff Epler and Fredrik Lundh.

import sys

import traceback

from codeop import CommandCompiler, compile_command

__all__ = ["InteractiveInterpreter", "InteractiveConsole", "interact",

"compile_command"]

class InteractiveInterpreter:

"""Base class for InteractiveConsole.

This class deals with parsing and interpreter state (the user's

namespace); it doesn't deal with input buffering or prompting or

input file naming (the filename is always passed in explicitly).

"""

def __init__(self, locals=None):

"""Constructor.

The optional 'locals' argument specifies the dictionary in

which code will be executed; it defaults to a newly created

dictionary with key "__name__" set to "__console__" and key

"__doc__" set to None.

"""

if locals is None:

locals = {"__name__": "__console__", "__doc__": None}

self.locals = locals

self.compile = CommandCompiler()

def runsource(self, source, filename="<input>", symbol="single"):

"""Compile and run some source in the interpreter.

Arguments are as for compile_command().

One several things can happen:

1) The input is incorrect; compile_command() raised an

exception (SyntaxError or OverflowError). A syntax traceback

will be printed by calling the showsyntaxerror() method.

2) The input is incomplete, and more input is required;

compile_command() returned None. Nothing happens.

3) The input is complete; compile_command() returned a code

object. The code is executed by calling self.runcode() (which

also handles run-time exceptions, except for SystemExit).

The return value is True in case 2, False in the other cases (unless

an exception is raised). The return value can be used to

decide whether to use sys.ps1 or sys.ps2 to prompt the next

line.

"""

try:

code = self.compile(source, filename, symbol)

except (OverflowError, SyntaxError, ValueError):

# Case 1

self.showsyntaxerror(filename)

return False

if code is None:

# Case 2

return True

# Case 3

self.runcode(code)

return False

def runcode(self, code):

"""Execute a code object.

When an exception occurs, self.showtraceback() is called to

display a traceback. All exceptions are caught except

SystemExit, which is reraised.

A note about KeyboardInterrupt: this exception may occur

elsewhere in this code, and may not always be caught. The

caller should be prepared to deal with it.

"""

try:

exec(code, self.locals)

except SystemExit:

raise

except:

self.showtraceback()

def showsyntaxerror(self, filename=None):

"""Display the syntax error that just occurred.

This doesn't display a stack trace because there isn't one.

If a filename is given, it is stuffed in the exception instead

of what was there before (because Python's parser always uses

"<string>" when reading from a string).

The output is written by self.write(), below.

"""

type, value, tb = sys.exc_info()

sys.last_type = type

sys.last_value = value

sys.last_traceback = tb

if filename and type is SyntaxError:

# Work hard to stuff the correct filename in the exception

try:

msg, (dummy_filename, lineno, offset, line) = value.args

except ValueError:

# Not the format we expect; leave it alone

pass

else:

# Stuff in the right filename

value = SyntaxError(msg, (filename, lineno, offset, line))

sys.last_value = value

if sys.excepthook is sys.__excepthook__:

lines = traceback.format_exception_only(type, value)

self.write(''.join(lines))

else:

# If someone has set sys.excepthook, we let that take precedence

# over self.write

sys.excepthook(type, value, tb)

def showtraceback(self):

"""Display the exception that just occurred.

We remove the first stack item because it is our own code.

The output is written by self.write(), below.

"""

sys.last_type, sys.last_value, last_tb = ei = sys.exc_info()

sys.last_traceback = last_tb

try:

lines = traceback.format_exception(ei[0], ei[1], last_tb.tb_next)

if sys.excepthook is sys.__excepthook__:

self.write(''.join(lines))

else:

# If someone has set sys.excepthook, we let that take precedence

# over self.write

sys.excepthook(ei[0], ei[1], last_tb)

finally:

last_tb = ei = None

def write(self, data):

"""Write a string.

The base implementation writes to sys.stderr; a subclass may

replace this with a different implementation.

"""

sys.stderr.write(data)

class InteractiveConsole(InteractiveInterpreter):

"""Closely emulate the behavior of the interactive Python interpreter.

This class builds on InteractiveInterpreter and adds prompting

using the familiar sys.ps1 and sys.ps2, and input buffering.

"""

def __init__(self, locals=None, filename="<console>"):

"""Constructor.

The optional locals argument will be passed to the

InteractiveInterpreter base class.

The optional filename argument should specify the (file)name

of the input stream; it will show up in tracebacks.

"""

InteractiveInterpreter.__init__(self, locals)

self.filename = filename

self.resetbuffer()

def resetbuffer(self):

"""Reset the input buffer."""

self.buffer = []

def interact(self, banner=None, exitmsg=None):

"""Closely emulate the interactive Python console.

The optional banner argument specifies the banner to print

before the first interaction; by default it prints a banner

similar to the one printed by the real Python interpreter,

followed by the current class name in parentheses (so as not

to confuse this with the real interpreter -- since it's so

close!).

The optional exitmsg argument specifies the exit message

printed when exiting. Pass the empty string to suppress

printing an exit message. If exitmsg is not given or None,

a default message is printed.

"""

try:

sys.ps1

except AttributeError:

sys.ps1 = ">>> "

try:

sys.ps2

except AttributeError:

sys.ps2 = "... "

cprt = 'Type "help", "copyright", "credits" or "license" for more information.'

if banner is None:

self.write("Python %s on %s\n%s\n(%s)\n" %

(sys.version, sys.platform, cprt,

self.__class__.__name__))

elif banner:

self.write("%s\n" % str(banner))

more = 0

while 1:

try:

if more:

prompt = sys.ps2

else:

prompt = sys.ps1

try:

line = self.raw_input(prompt)

except EOFError:

self.write("\n")

break

else:

more = self.push(line)

except KeyboardInterrupt:

self.write("\nKeyboardInterrupt\n")

self.resetbuffer()

more = 0

if exitmsg is None:

self.write('now exiting %s...\n' % self.__class__.__name__)

elif exitmsg != '':

self.write('%s\n' % exitmsg)

def push(self, line):

"""Push a line to the interpreter.

The line should not have a trailing newline; it may have

internal newlines. The line is appended to a buffer and the

interpreter's runsource() method is called with the

concatenated contents of the buffer as source. If this

indicates that the command was executed or invalid, the buffer

is reset; otherwise, the command is incomplete, and the buffer

is left as it was after the line was appended. The return

value is 1 if more input is required, 0 if the line was dealt

with in some way (this is the same as runsource()).

"""

self.buffer.append(line)

source = "\n".join(self.buffer)

more = self.runsource(source, self.filename)

if not more:

self.resetbuffer()

return more

def raw_input(self, prompt=""):

"""Write a prompt and read a line.

The returned line does not include the trailing newline.

When the user enters the EOF key sequence, EOFError is raised.

The base implementation uses the built-in function

input(); a subclass may replace this with a different

implementation.

"""

return input(prompt)

def interact(banner=None, readfunc=None, local=None, exitmsg=None):

"""Closely emulate the interactive Python interpreter.

This is a backwards compatible interface to the InteractiveConsole

class. When readfunc is not specified, it attempts to import the

readline module to enable GNU readline if it is available.

Arguments (all optional, all default to None):

banner -- passed to InteractiveConsole.interact()

readfunc -- if not None, replaces InteractiveConsole.raw_input()

local -- passed to InteractiveInterpreter.__init__()

exitmsg -- passed to InteractiveConsole.interact()

"""

console = InteractiveConsole(local)

if readfunc is not None:

console.raw_input = readfunc

else:

try:

import readline

except ImportError:

pass

console.interact(banner, exitmsg)

if __name__ == "__main__":

import argparse

parser = argparse.ArgumentParser()

parser.add_argument('-q', action='store_true',

help="don't print version and copyright messages")

args = parser.parse_args()

if args.q or sys.flags.quiet:

banner = ''

else:

banner = None

interact(banner)

cpython/Lib/code.py at tkinter_docs · native-api/cpython · GitHub

Repository navigation

Expand file tree

Breadcrumbs

code.py

Latest commit

History

Breadcrumbs

code.py

File metadata and controls