IPthon help and documentation

  1. Using a symbol? Get the document
  2. Use symbol?? Get the source code (when the query object is not implemented in Python, but implemented in C or another compiled extension language, the suffix?? Equivalent to?)
  3. The TAB completion
    • TAB completion of object content
      • You can narrow the match by entering the first or first few characters of the property or method name
      • An underscore indicates a private property or method
    • Automatic TAB completion during import
    • Wildcard * matches (matches any string, including empty strings)

Shortcuts in IPython shell

Implemented through IPthon's dependency on the GNU Readline libraryCopy the code
  1. Navigation shortcut
  2. Text input shortcut keys
  3. Command history shortcut keys

    Ctrl+ R goes beyond the current session to access the SQLite database stored in the Ipython configuration file path

  4. other

IPython magic command

  • Line magic: prefixed with a single character % on a single line of input.
  • Unit magic: prefixed with two %% s on multiple lines of input
  1. Paste code blocks: %paset and %cpaste
  • The %paste command enters and executes the copied code
  • The %cpaste command turns on the interactive multi-line input prompt
  1. Execute external code: %run
  • %run [py filename]
  1. Calculate the code runtime: %timeit
  • %timeit: Automatically calculates the execution time of the next line of Python statements
  • %%timeit: used for multi-line statements
  • List synthesis is faster than the equivalent for loop
  1. Magic function help:? Magic, % and % lsmagic
  • %magic: Gets descriptions and examples of all available magic functions
  • %lsmagic: Gets a list of all available magic functions

Input and output history

  1. Input-output object
    • When In is printed, the first element of the list is a placeholder so that In[1] represents the first instruction
    • In for list, Out for dictionary (no output without value)
    • Reference the previous result directly using the index Out[n]
  2. Underscore shortcut key
    • Gets the previous output and skips instructions that have no output. The number of underscores within three is the first several outputs
    • If there are more than three, use line numbers (short for Out[X] : _X
  3. Disallow output: semicolon ‘; ‘, the output will not be displayed on the screen or stored in the Out path
  4. Related magic command
    • %histry
    %history -n 1-8# represents input from one to eight
    • %save
    • %rerun