pythonstartup py_python py_python py_python tcl_library tk_library eoferror exception __eq__ method equality built-in object types - shared references and - testing truth values - value equality operators equivalence (==operator errno module error handling displaying errors and tracebacks exceptions and missing keys - scripts and testing inputs with try statements - escape sequences - etree package eval built-in function jump tables and strings and event notification exception class about as catchall user-defined exceptions and exception classes about - built-in - coding - custom data and behavior - custom print displays hierarchies in - quiz questions and answers version considerations exception handlers (see also specific statementsabout backtracking and default defining methods for - index interactive prompt and nesting - termination actions and exception variables exceptions (see also specific exceptions and specific statementsabout built-in catching - catching too little catching too much - chaining - class-based - coding details - common roles design tips and gotchas - errors versus propagating quiz questions and answers raising string-based usage considerations - user-defined exceptions module exec built-in function - execfile built-in function executable scripts #comment in windows - about env program executing programs (see program executionexercises part - - part ii - - part iii - - part iv - - part - - part vi - - part vii - __exit__ method explicit attributes exponentiation operation expression operators converting mixed types grouping with parentheses listed operator overloading