• curses.ascii —- Utilities for ASCII characters

    curses.ascii —- Utilities for ASCII characters


    The curses.ascii module supplies name constants for ASCII characters andfunctions to test membership in various ASCII character classes. The constantssupplied are names for control characters as follows:

    名称意义
    NUL
    SOHStart of heading, console interrupt
    STXStart of text
    ETXEnd of text
    EOTEnd of transmission
    ENQEnquiry, goes with ACK flow control
    ACKAcknowledgement
    BELBell
    BSBackspace
    TABTab
    HTAlias for TAB: "Horizontal tab"
    LFLine feed
    NLAlias for LF: "New line"
    VTVertical tab
    FFForm feed
    CRCarriage return
    SOShift-out, begin alternate character set
    SIShift-in, resume default character set
    DLEData-link escape
    DC1XON, for flow control
    DC2Device control 2, block-mode flow control
    DC3XOFF, for flow control
    DC4Device control 4
    NAKNegative acknowledgement
    SYNSynchronous idle
    ETBEnd transmission block
    CAN取消
    EMEnd of medium
    SUBSubstitute
    ESCEscape
    FSFile separator
    GSGroup separator
    RS记录分隔符,块模式终结器
    US单位分隔符
    SP空格
    DEL删除

    Note that many of these have little practical significance in modern usage. Themnemonics derive from teleprinter conventions that predate digital computers.

    The module supplies the following functions, patterned on those in the standardC library:

    • curses.ascii.isalnum(c)
    • Checks for an ASCII alphanumeric character; it is equivalent to isalpha(c) orisdigit(c).

    • curses.ascii.isalpha(c)

    • Checks for an ASCII alphabetic character; it is equivalent to isupper(c) orislower(c).

    • curses.ascii.isascii(c)

    • Checks for a character value that fits in the 7-bit ASCII set.

    • curses.ascii.isblank(c)

    • Checks for an ASCII whitespace character; space or horizontal tab.

    • curses.ascii.iscntrl(c)

    • Checks for an ASCII control character (in the range 0x00 to 0x1f or 0x7f).

    • curses.ascii.isdigit(c)

    • Checks for an ASCII decimal digit, '0' through '9'. This is equivalentto c in string.digits.

    • curses.ascii.isgraph(c)

    • Checks for ASCII any printable character except space.

    • curses.ascii.islower(c)

    • Checks for an ASCII lower-case character.

    • curses.ascii.isprint(c)

    • Checks for any ASCII printable character including space.

    • curses.ascii.ispunct(c)

    • Checks for any printable ASCII character which is not a space or an alphanumericcharacter.

    • curses.ascii.isspace(c)

    • Checks for ASCII white-space characters; space, line feed, carriage return, formfeed, horizontal tab, vertical tab.

    • curses.ascii.isupper(c)

    • Checks for an ASCII uppercase letter.

    • curses.ascii.isxdigit(c)

    • Checks for an ASCII hexadecimal digit. This is equivalent to c instring.hexdigits.

    • curses.ascii.isctrl(c)

    • Checks for an ASCII control character (ordinal values 0 to 31).

    • curses.ascii.ismeta(c)

    • Checks for a non-ASCII character (ordinal values 0x80 and above).

    These functions accept either integers or single-character strings; when the argument is astring, it is first converted using the built-in function ord().

    Note that all these functions check ordinal bit values derived from thecharacter of the string you pass in; they do not actually know anything aboutthe host machine's character encoding.

    The following two functions take either a single-character string or integerbyte value; they return a value of the same type.

    • curses.ascii.ascii(c)
    • Return the ASCII value corresponding to the low 7 bits of c.

    • curses.ascii.ctrl(c)

    • Return the control character corresponding to the given character (the characterbit value is bitwise-anded with 0x1f).

    • curses.ascii.alt(c)

    • Return the 8-bit character corresponding to the given ASCII character (thecharacter bit value is bitwise-ored with 0x80).

    The following function takes either a single-character string or integer value;it returns a string.

    • curses.ascii.unctrl(c)
    • Return a string representation of the ASCII character c. If c is printable,this string is the character itself. If the character is a control character(0x00—0x1f) the string consists of a caret ('^') followed by thecorresponding uppercase letter. If the character is an ASCII delete (0x7f) thestring is '^?'. If the character has its meta bit (0x80) set, the meta bitis stripped, the preceding rules applied, and '!' prepended to the result.

    • curses.ascii.controlnames

    • A 33-element string array that contains the ASCII mnemonics for the thirty-twoASCII control characters from 0 (NUL) to 0x1f (US), in order, plus the mnemonicSP for the space character.