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110 lines
3.3 KiB
Python
110 lines
3.3 KiB
Python
"""Utilities dealing with code objects."""
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def compile_command(source, filename="<input>", symbol="single"):
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r"""Compile a command and determine whether it is incomplete.
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Arguments:
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source -- the source string; may contain \n characters
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filename -- optional filename from which source was read; default "<input>"
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symbol -- optional grammar start symbol; "single" (default) or "eval"
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Return value / exception raised:
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- Return a code object if the command is complete and valid
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- Return None if the command is incomplete
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- Raise SyntaxError if the command is a syntax error
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Approach:
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Compile three times: as is, with \n, and with \n\n appended. If
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it compiles as is, it's complete. If it compiles with one \n
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appended, we expect more. If it doesn't compile either way, we
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compare the error we get when compiling with \n or \n\n appended.
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If the errors are the same, the code is broken. But if the errors
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are different, we expect more. Not intuitive; not even guaranteed
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to hold in future releases; but this matches the compiler's
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behavior in Python 1.4 and 1.5.
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"""
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err = err1 = err2 = None
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code = code1 = code2 = None
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try:
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code = compile(source, filename, symbol)
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except SyntaxError, err:
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pass
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try:
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code1 = compile(source + "\n", filename, symbol)
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except SyntaxError, err1:
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pass
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try:
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code2 = compile(source + "\n\n", filename, symbol)
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except SyntaxError, err2:
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pass
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if code:
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return code
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try:
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e1 = err1.__dict__
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except AttributeError:
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e1 = err1
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try:
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e2 = err2.__dict__
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except AttributeError:
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e2 = err2
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if not code1 and e1 == e2:
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raise SyntaxError, err1
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def interact(banner=None, readfunc=raw_input, local=None):
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# Due to Jeff Epler, with changes by Guido:
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"""Closely emulate the interactive Python console."""
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try: import readline # Enable GNU readline if available
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except: pass
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local = local or {}
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import sys, string, traceback
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sys.ps1 = '>>> '
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sys.ps2 = '... '
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if banner:
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print banner
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else:
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print "Python Interactive Console", sys.version
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print sys.copyright
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buf = []
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while 1:
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if buf: prompt = sys.ps2
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else: prompt = sys.ps1
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try: line = readfunc(prompt)
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except KeyboardInterrupt:
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print "\nKeyboardInterrupt"
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buf = []
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continue
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except EOFError: break
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buf.append(line)
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try: x = compile_command(string.join(buf, "\n"))
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except SyntaxError:
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traceback.print_exc(0)
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buf = []
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continue
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if x == None: continue
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else:
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try: exec x in local
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except:
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exc_type, exc_value, exc_traceback = \
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sys.exc_type, sys.exc_value, \
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sys.exc_traceback
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l = len(traceback.extract_tb(sys.exc_traceback))
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try: 1/0
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except:
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m = len(traceback.extract_tb(
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sys.exc_traceback))
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traceback.print_exception(exc_type,
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exc_value, exc_traceback, l-m)
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buf = []
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if __name__ == '__main__':
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interact()
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