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
• 15.3. 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. description
    • 15.4.2.2. epilog
    • 15.4.2.3. add_help
    • 15.4.2.4. prefix_chars
    • 15.4.2.5. fromfile_prefix_chars
    • 15.4.2.6. argument_default
    • 15.4.2.7. parents
    • 15.4.2.8. formatter_class
    • 15.4.2.9. conflict_handler
    • 15.4.2.10. prog
    • 15.4.2.11. usage
  • 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
  • 15.4.4. 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
    • 15.4.4.5. Beyond sys.argv
    • 15.4.4.6. Custom namespaces
  • 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
    • 15.5.2.7. 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. Logging tutorial
    • 15.7.1.1. Simple examples
    • 15.7.1.2. Loggers
    • 15.7.1.3. Handlers
    • 15.7.1.4. Formatters
    • 15.7.1.5. Configuring Logging
    • 15.7.1.6. Configuring Logging for a Library
  • 15.7.2. Logging Levels
    • 15.7.2.1. Custom Levels
  • 15.7.3. Useful Handlers
  • 15.7.4. Module-Level Functions
  • 15.7.5. Logger Objects
  • 15.7.6. Basic example
  • 15.7.7. Logging to multiple destinations
  • 15.7.8. Exceptions raised during logging
  • 15.7.9. Adding contextual information to your logging output
    • 15.7.9.1. Using LoggerAdapters to impart contextual information
    • 15.7.9.2. Using Filters to impart contextual information
  • 15.7.10. Logging to a single file from multiple processes
  • 15.7.11. Sending and receiving logging events across a network
  • 15.7.12. Using arbitrary objects as messages
  • 15.7.13. Optimization
  • 15.7.14. Handler Objects
    • 15.7.14.1. StreamHandler
    • 15.7.14.2. FileHandler
    • 15.7.14.3. NullHandler
    • 15.7.14.4. WatchedFileHandler
    • 15.7.14.5. RotatingFileHandler
    • 15.7.14.6. TimedRotatingFileHandler
    • 15.7.14.7. SocketHandler
    • 15.7.14.8. DatagramHandler
    • 15.7.14.9. SysLogHandler
    • 15.7.14.10. NTEventLogHandler
    • 15.7.14.11. SMTPHandler
    • 15.7.14.12. MemoryHandler
    • 15.7.14.13. HTTPHandler
  • 15.7.15. Formatter Objects
  • 15.7.16. Filter Objects
    • 15.7.16.1. Other uses for filters
  • 15.7.17. LogRecord Objects
  • 15.7.18. LoggerAdapter Objects
  • 15.7.19. Thread Safety
  • 15.7.20. Integration with the warnings module
  • 15.7.21. Configuration
    • 15.7.21.1. Configuration functions
    • 15.7.21.2. Configuration dictionary schema
      • 15.7.21.2.1. Dictionary Schema Details
      • 15.7.21.2.2. Incremental Configuration
      • 15.7.21.2.3. Object connections
      • 15.7.21.2.4. User-defined objects
      • 15.7.21.2.5. Access to external objects
      • 15.7.21.2.6. Access to internal objects
    • 15.7.21.3. Configuration file format
    • 15.7.21.4. Configuration server example
  • 15.7.22. More examples
    • 15.7.22.1. Multiple handlers and formatters
    • 15.7.22.2. Using logging in multiple modules
• 15.8. getpass — Portable password input
• 15.9. curses — Terminal handling for character-cell displays
  • 15.9.1. Functions
  • 15.9.2. Window Objects
  • 15.9.3. Constants
• 15.10. curses.textpad — Text input widget for curses programs
  • 15.10.1. Textbox objects
• 15.11. curses.wrapper — Terminal handler for curses programs
• 15.12. curses.ascii — Utilities for ASCII characters
• 15.13. curses.panel — A panel stack extension for curses
  • 15.13.1. Functions
  • 15.13.2. Panel Objects
• 15.14. platform — Access to underlying platform’s identifying data
  • 15.14.1. Cross Platform
  • 15.14.2. Java Platform
  • 15.14.3. Windows Platform
    • 15.14.3.1. Win95/98 specific
  • 15.14.4. Mac OS Platform
  • 15.14.5. Unix Platforms
• 15.15. errno — Standard errno system symbols
• 15.16. ctypes — A foreign function library for Python
  • 15.16.1. ctypes tutorial
    • 15.16.1.1. Loading dynamic link libraries
    • 15.16.1.2. Accessing functions from loaded dlls
    • 15.16.1.3. Calling functions
    • 15.16.1.4. Fundamental data types
    • 15.16.1.5. Calling functions, continued
    • 15.16.1.6. Calling functions with your own custom data types
    • 15.16.1.7. Specifying the required argument types (function prototypes)
    • 15.16.1.8. Return types
    • 15.16.1.9. Passing pointers (or: passing parameters by reference)
    • 15.16.1.10. Structures and unions
    • 15.16.1.11. Structure/union alignment and byte order
    • 15.16.1.12. Bit fields in structures and unions
    • 15.16.1.13. Arrays
    • 15.16.1.14. Pointers
    • 15.16.1.15. Type conversions
    • 15.16.1.16. Incomplete Types
    • 15.16.1.17. Callback functions
    • 15.16.1.18. Accessing values exported from dlls
    • 15.16.1.19. Surprises
    • 15.16.1.20. Variable-sized data types
  • 15.16.2. ctypes reference
    • 15.16.2.1. Finding shared libraries
    • 15.16.2.2. Loading shared libraries
    • 15.16.2.3. Foreign functions
    • 15.16.2.4. Function prototypes
    • 15.16.2.5. Utility functions
    • 15.16.2.6. Data types
    • 15.16.2.7. Fundamental data types
    • 15.16.2.8. Structured data types
    • 15.16.2.9. Arrays and pointers