""" Python shell for SymPy. This is just a normal Python shell (IPython shell if you have the IPython package installed), that executes the following commands for the user: >>> from __future__ import division >>> from sympy import * >>> x, y, z, t = symbols('x y z t') >>> k, m, n = symbols('k m n', integer=True) >>> f, g, h = symbols('f g h', cls=Function) >>> init_printing() So starting 'isympy' is equivalent to starting Python (or IPython) and executing the above commands by hand. It is intended for easy and quick experimentation with SymPy. isympy is a good way to use SymPy as an interactive calculator. If you have IPython and Matplotlib installed, then interactive plotting is enabled by default. COMMAND LINE OPTIONS -------------------- -c CONSOLE, --console=CONSOLE Use the specified shell (Python or IPython) shell as the console backend instead of the default one (IPython if present, Python otherwise), e.g.: $isympy -c python CONSOLE must be one of 'ipython' or 'python' -p PRETTY, --pretty PRETTY Setup pretty-printing in SymPy. When pretty-printing is enabled, expressions can be printed with Unicode or ASCII. The default is to use pretty-printing (with Unicode if the terminal supports it). When this option is 'no', expressions will not be pretty-printed and ASCII will be used: $isympy -p no PRETTY must be one of 'unicode', 'ascii', or 'no' -t TYPES, --types=TYPES Setup the ground types for the polys. By default, gmpy ground types are used if gmpy2 or gmpy is installed, otherwise it falls back to python ground types, which are a little bit slower. You can manually choose python ground types even if gmpy is installed (e.g., for testing purposes): $isympy -t python TYPES must be one of 'gmpy', 'gmpy1' or 'python' Note that the ground type gmpy1 is primarily intended for testing; it forces the use of gmpy version 1 even if gmpy2 is available. This is the same as setting the environment variable SYMPY_GROUND_TYPES to the given ground type (e.g., SYMPY_GROUND_TYPES='gmpy') The ground types can be determined interactively from the variable sympy.polys.domains.GROUND_TYPES. -o ORDER, --order ORDER Setup the ordering of terms for printing. The default is lex, which orders terms lexicographically (e.g., x**2 + x + 1). You can choose other orderings, such as rev-lex, which will use reverse lexicographic ordering (e.g., 1 + x + x**2): $isympy -o rev-lex ORDER must be one of 'lex', 'rev-lex', 'grlex', 'rev-grlex', 'grevlex', 'rev-grevlex', 'old', or 'none'. Note that for very large expressions, ORDER='none' may speed up printing considerably but the terms will have no canonical order. -q, --quiet Print only Python's and SymPy's versions to stdout at startup. -d, --doctest Use the same format that should be used for doctests. This is equivalent to -c python -p no. -C, --no-cache Disable the caching mechanism. Disabling the cache may slow certain operations down considerably. This is useful for testing the cache, or for benchmarking, as the cache can result in deceptive timings. This is equivalent to setting the environment variable SYMPY_USE_CACHE to 'no'. -a, --auto-symbols (requires at least IPython 0.11) Automatically create missing symbols. Normally, typing a name of a Symbol that has not been instantiated first would raise NameError, but with this option enabled, any undefined name will be automatically created as a Symbol. Note that this is intended only for interactive, calculator style usage. In a script that uses SymPy, Symbols should be instantiated at the top, so that it's clear what they are. This will not override any names that are already defined, which includes the single character letters represented by the mnemonic QCOSINE (see the "Gotchas and Pitfalls" document in the documentation). You can delete existing names by executing "del name". If a name is defined, typing "'name' in dir()" will return True. The Symbols that are created using this have default assumptions. If you want to place assumptions on symbols, you should create them using symbols() or var(). Finally, this only works in the top level namespace. So, for example, if you define a function in isympy with an undefined Symbol, it will not work. See also the -i and -I options. -i, --int-to-Integer (requires at least IPython 0.11) Automatically wrap int literals with Integer. This makes it so that things like 1/2 will come out as Rational(1, 2), rather than 0.5. This works by preprocessing the source and wrapping all int literals with Integer. Note that this will not change the behavior of int literals assigned to variables, and it also won't change the behavior of functions that return int literals. If you want an int, you can wrap the literal in int(), e.g. int(3)/int(2) gives 1.5 (with division imported from __future__). -I, --interactive (requires at least IPython 0.11) This is equivalent to --auto-symbols --int-to-Integer. Future options designed for ease of interactive use may be added to this. -D, --debug Enable debugging output. This is the same as setting the environment variable SYMPY_DEBUG to 'True'. The debug status is set in the variable SYMPY_DEBUG within isympy. -- IPython options Additionally you can pass command line options directly to the IPython interpreter (the standard Python shell is not supported). However you need to add the '--' separator between two types of options, e.g the startup banner option and the colors option. You need to enter the options as required by the version of IPython that you are using, too: in IPython 0.11, $isympy -q -- --colors=NoColor or older versions of IPython, $isympy -q -- -colors NoColor See also isympy --help. """ import os import sys # DO NOT IMPORT SYMPY HERE! Or the setting of the sympy environment variables # by the command line will break. def main() -> None: from argparse import ArgumentParser, RawDescriptionHelpFormatter VERSION = None if '--version' in sys.argv: # We cannot import sympy before this is run, because flags like -C and # -t set environment variables that must be set before SymPy is # imported. The only thing we need to import it for is to get the # version, which only matters with the --version flag. import sympy VERSION = sympy.__version__ usage = 'isympy [options] -- [ipython options]' parser = ArgumentParser( usage=usage, description=__doc__, formatter_class=RawDescriptionHelpFormatter, ) parser.add_argument('--version', action='version', version=VERSION) parser.add_argument( '-c', '--console', dest='console', action='store', default=None, choices=['ipython', 'python'], metavar='CONSOLE', help='select type of interactive session: ipython | python; defaults ' 'to ipython if IPython is installed, otherwise python') parser.add_argument( '-p', '--pretty', dest='pretty', action='store', default=None, metavar='PRETTY', choices=['unicode', 'ascii', 'no'], help='setup pretty printing: unicode | ascii | no; defaults to ' 'unicode printing if the terminal supports it, otherwise ascii') parser.add_argument( '-t', '--types', dest='types', action='store', default=None, metavar='TYPES', choices=['gmpy', 'gmpy1', 'python'], help='setup ground types: gmpy | gmpy1 | python; defaults to gmpy if gmpy2 ' 'or gmpy is installed, otherwise python') parser.add_argument( '-o', '--order', dest='order', action='store', default=None, metavar='ORDER', choices=['lex', 'grlex', 'grevlex', 'rev-lex', 'rev-grlex', 'rev-grevlex', 'old', 'none'], help='setup ordering of terms: [rev-]lex | [rev-]grlex | [rev-]grevlex | old | none; defaults to lex') parser.add_argument( '-q', '--quiet', dest='quiet', action='store_true', default=False, help='print only version information at startup') parser.add_argument( '-d', '--doctest', dest='doctest', action='store_true', default=False, help='use the doctest format for output (you can just copy and paste it)') parser.add_argument( '-C', '--no-cache', dest='cache', action='store_false', default=True, help='disable caching mechanism') parser.add_argument( '-a', '--auto-symbols', dest='auto_symbols', action='store_true', default=False, help='automatically construct missing symbols') parser.add_argument( '-i', '--int-to-Integer', dest='auto_int_to_Integer', action='store_true', default=False, help="automatically wrap int literals with Integer") parser.add_argument( '-I', '--interactive', dest='interactive', action='store_true', default=False, help="equivalent to -a -i") parser.add_argument( '-D', '--debug', dest='debug', action='store_true', default=False, help='enable debugging output') (options, ipy_args) = parser.parse_known_args() if '--' in ipy_args: ipy_args.remove('--') if not options.cache: os.environ['SYMPY_USE_CACHE'] = 'no' if options.types: os.environ['SYMPY_GROUND_TYPES'] = options.types if options.debug: os.environ['SYMPY_DEBUG'] = str(options.debug) if options.doctest: options.pretty = 'no' options.console = 'python' session = options.console if session is not None: ipython = session == 'ipython' else: try: import IPython ipython = True except ImportError: if not options.quiet: from sympy.interactive.session import no_ipython print(no_ipython) ipython = False args = { 'pretty_print': True, 'use_unicode': None, 'use_latex': None, 'order': None, 'argv': ipy_args, } if options.pretty == 'unicode': args['use_unicode'] = True elif options.pretty == 'ascii': args['use_unicode'] = False elif options.pretty == 'no': args['pretty_print'] = False if options.order is not None: args['order'] = options.order args['quiet'] = options.quiet args['auto_symbols'] = options.auto_symbols or options.interactive args['auto_int_to_Integer'] = options.auto_int_to_Integer or options.interactive from sympy.interactive import init_session init_session(ipython, **args) if __name__ == "__main__": main()