15. Generic Operating System Services

The modules described in this chapter provide interfaces to operating system features that are available on (almost) all operating systems, such as files and a clock. The interfaces are generally modeled after the Unix or C interfaces, but they are available on most other systems as well. Here’s an overview:

• 15.1. os — Miscellaneous operating system interfaces
  • 15.1.1. Process Parameters
  • 15.1.2. File Object Creation
  • 15.1.3. File Descriptor Operations
    • 15.1.3.1. open() flag constants
  • 15.1.4. Files and Directories
  • 15.1.5. Process Management
  • 15.1.6. Miscellaneous System Information
  • 15.1.7. Miscellaneous Functions
• 15.2. io — Core tools for working with streams
  • 15.2.1. Module Interface
  • 15.2.2. I/O Base Classes
  • 15.2.3. Raw File I/O
  • 15.2.4. Buffered Streams
  • 15.2.5. Text I/O
  • 15.2.6. Advanced topics
    • 15.2.6.1. Performance
      • 15.2.6.1.1. Binary I/O
      • 15.2.6.1.2. Text I/O
    • 15.2.6.2. Multi-threading
    • 15.2.6.3. Reentrancy
• 15.3. time — Time access and conversions
• 15.4. argparse — Parser for command-line options, arguments and sub-commands
  • 15.4.1. Example
    • 15.4.1.1. Creating a parser
    • 15.4.1.2. Adding arguments
    • 15.4.1.3. Parsing arguments
  • 15.4.2. ArgumentParser objects
    • 15.4.2.1. prog
    • 15.4.2.2. usage
    • 15.4.2.3. description
    • 15.4.2.4. epilog
    • 15.4.2.5. parents
    • 15.4.2.6. formatter_class
    • 15.4.2.7. prefix_chars
    • 15.4.2.8. fromfile_prefix_chars
    • 15.4.2.9. argument_default
    • 15.4.2.10. conflict_handler
    • 15.4.2.11. add_help
  • 15.4.3. The add_argument() method
    • 15.4.3.1. name or flags
    • 15.4.3.2. action
    • 15.4.3.3. nargs
    • 15.4.3.4. const
    • 15.4.3.5. default
    • 15.4.3.6. type
    • 15.4.3.7. choices
    • 15.4.3.8. required
    • 15.4.3.9. help
    • 15.4.3.10. metavar
    • 15.4.3.11. dest
    • 15.4.3.12. Action classes
  • 15.4.4. The parse_args() method
    • 15.4.4.1. Option value syntax
    • 15.4.4.2. Invalid arguments
    • 15.4.4.3. Arguments containing -
    • 15.4.4.4. Argument abbreviations (prefix matching)
    • 15.4.4.5. Beyond sys.argv
    • 15.4.4.6. The Namespace object
  • 15.4.5. Other utilities
    • 15.4.5.1. Sub-commands
    • 15.4.5.2. FileType objects
    • 15.4.5.3. Argument groups
    • 15.4.5.4. Mutual exclusion
    • 15.4.5.5. Parser defaults
    • 15.4.5.6. Printing help
    • 15.4.5.7. Partial parsing
    • 15.4.5.8. Customizing file parsing
    • 15.4.5.9. Exiting methods
  • 15.4.6. Upgrading optparse code
• 15.5. optparse — Parser for command line options
  • 15.5.1. Background
    • 15.5.1.1. Terminology
    • 15.5.1.2. What are options for?
    • 15.5.1.3. What are positional arguments for?
  • 15.5.2. Tutorial
    • 15.5.2.1. Understanding option actions
    • 15.5.2.2. The store action
    • 15.5.2.3. Handling boolean (flag) options
    • 15.5.2.4. Other actions
    • 15.5.2.5. Default values
    • 15.5.2.6. Generating help
      • 15.5.2.6.1. Grouping Options
    • 15.5.2.7. Printing a version string
    • 15.5.2.8. How optparse handles errors
    • 15.5.2.9. Putting it all together
  • 15.5.3. Reference Guide
    • 15.5.3.1. Creating the parser
    • 15.5.3.2. Populating the parser
    • 15.5.3.3. Defining options
    • 15.5.3.4. Option attributes
    • 15.5.3.5. Standard option actions
    • 15.5.3.6. Standard option types
    • 15.5.3.7. Parsing arguments
    • 15.5.3.8. Querying and manipulating your option parser
    • 15.5.3.9. Conflicts between options
    • 15.5.3.10. Cleanup
    • 15.5.3.11. Other methods
  • 15.5.4. Option Callbacks
    • 15.5.4.1. Defining a callback option
    • 15.5.4.2. How callbacks are called
    • 15.5.4.3. Raising errors in a callback
    • 15.5.4.4. Callback example 1: trivial callback
    • 15.5.4.5. Callback example 2: check option order
    • 15.5.4.6. Callback example 3: check option order (generalized)
    • 15.5.4.7. Callback example 4: check arbitrary condition
    • 15.5.4.8. Callback example 5: fixed arguments
    • 15.5.4.9. Callback example 6: variable arguments
  • 15.5.5. Extending optparse
    • 15.5.5.1. Adding new types
    • 15.5.5.2. Adding new actions
• 15.6. getopt — C-style parser for command line options
• 15.7. logging — Logging facility for Python
  • 15.7.1. Logger Objects
  • 15.7.2. Logging Levels
  • 15.7.3. Handler Objects
  • 15.7.4. Formatter Objects
  • 15.7.5. Filter Objects
  • 15.7.6. LogRecord Objects
  • 15.7.7. LogRecord attributes
  • 15.7.8. LoggerAdapter Objects
  • 15.7.9. Thread Safety
  • 15.7.10. Module-Level Functions
  • 15.7.11. Integration with the warnings module
• 15.8. logging.config — Logging configuration
  • 15.8.1. Configuration functions
  • 15.8.2. Configuration dictionary schema
    • 15.8.2.1. Dictionary Schema Details
    • 15.8.2.2. Incremental Configuration
    • 15.8.2.3. Object connections
    • 15.8.2.4. User-defined objects
    • 15.8.2.5. Access to external objects
    • 15.8.2.6. Access to internal objects
    • 15.8.2.7. Import resolution and custom importers
  • 15.8.3. Configuration file format
• 15.9. logging.handlers — Logging handlers
  • 15.9.1. StreamHandler
  • 15.9.2. FileHandler
  • 15.9.3. NullHandler
  • 15.9.4. WatchedFileHandler
  • 15.9.5. RotatingFileHandler
  • 15.9.6. TimedRotatingFileHandler
  • 15.9.7. SocketHandler
  • 15.9.8. DatagramHandler
  • 15.9.9. SysLogHandler
  • 15.9.10. NTEventLogHandler
  • 15.9.11. SMTPHandler
  • 15.9.12. MemoryHandler
  • 15.9.13. HTTPHandler
• 15.10. getpass — Portable password input
• 15.11. curses — Terminal handling for character-cell displays
  • 15.11.1. Functions
  • 15.11.2. Window Objects
  • 15.11.3. Constants
• 15.12. curses.textpad — Text input widget for curses programs
  • 15.12.1. Textbox objects
• 15.13. curses.ascii — Utilities for ASCII characters
• 15.14. curses.panel — A panel stack extension for curses
  • 15.14.1. Functions
  • 15.14.2. Panel Objects
• 15.15. platform — Access to underlying platform’s identifying data
  • 15.15.1. Cross Platform
  • 15.15.2. Java Platform
  • 15.15.3. Windows Platform
    • 15.15.3.1. Win95/98 specific
  • 15.15.4. Mac OS Platform
  • 15.15.5. Unix Platforms
• 15.16. errno — Standard errno system symbols
• 15.17. ctypes — A foreign function library for Python
  • 15.17.1. ctypes tutorial
    • 15.17.1.1. Loading dynamic link libraries
    • 15.17.1.2. Accessing functions from loaded dlls
    • 15.17.1.3. Calling functions
    • 15.17.1.4. Fundamental data types
    • 15.17.1.5. Calling functions, continued
    • 15.17.1.6. Calling functions with your own custom data types
    • 15.17.1.7. Specifying the required argument types (function prototypes)
    • 15.17.1.8. Return types
    • 15.17.1.9. Passing pointers (or: passing parameters by reference)
    • 15.17.1.10. Structures and unions
    • 15.17.1.11. Structure/union alignment and byte order
    • 15.17.1.12. Bit fields in structures and unions
    • 15.17.1.13. Arrays
    • 15.17.1.14. Pointers
    • 15.17.1.15. Type conversions
    • 15.17.1.16. Incomplete Types
    • 15.17.1.17. Callback functions
    • 15.17.1.18. Accessing values exported from dlls
    • 15.17.1.19. Surprises
    • 15.17.1.20. Variable-sized data types
  • 15.17.2. ctypes reference
    • 15.17.2.1. Finding shared libraries
    • 15.17.2.2. Loading shared libraries
    • 15.17.2.3. Foreign functions
    • 15.17.2.4. Function prototypes
    • 15.17.2.5. Utility functions
    • 15.17.2.6. Data types
    • 15.17.2.7. Fundamental data types
    • 15.17.2.8. Structured data types
    • 15.17.2.9. Arrays and pointers