Takes input files or other data, and replaces certain strings with variables or functions. More...

Detailed Description

Takes input files or other data, and replaces certain strings with variables or functions.

The calling convention is quite simple:

 ap=ATParser(varhash={"NAME":"Katrina", "STID":"12L"})
 ap.parse_file("input-file.txt")
 lines="line 1\nline 2\nline 3 of @[NAME]"
 ap.parse_lines(lines,"(string-data)")
 ap.parse_stream(sys.stdin,"(stdin)")

Inputs are general strings with @[...] and @** escape sequences which follow familiar shell syntax (but with @[...] instead of ${...}):

1 My storm is @[NAME] and the RSMC is @[RSMC:-${center:-unknown}].

In this case, it would print:

1 My storm is Katrina and the RSMC is unknown.

since NAME is set, but RSMC and center are unset.

There are also block if statements:

 @** if NAME==BILLY
 storm is billy
 @** elseif name==KATRINA
 storm is katrina
 @** else
 another storm
 @** endif

and a variety of other things:

 @[<anotherfile.txt]  # read another file
 @[var=value] # assign a variable
 @[var:=value] # assign a variable and insert the value in the output stream
 @[var2:?] # abort if var2 is not assigned, otherwise insert var2's contents
 @[var3==BLAH?thencondition:elsecondition] # if-then-else substitution
 @[var3!=BLAH?thencondition:elsecondition] # same, but with a "not equal"
 @[var4:-substitution] # insert var4, or this substitution if var4 is unset
 @[var5:+text] # insert text if var5 is set

There are also a small number of functions that modify text before it is sent to stdout. (The original variable is unmodified, only the output text is changed.)

 @[var1.uc] # uppercase value of var1
 @[var1.lc] # lowercase value of var1
 @[var1.len] # length of var1
 @[var1.trim] # var1 with leading and trailing whitespace removed

Definition at line 98 of file atparse.py.

Public Member Functions
def	__init__
	ATParser constructor. More...

def	max_lines (self)
	The maximum number of lines to read. More...

def	infile (self)
	The current input file name. More...

def	parse_stream (self, stream, streamname)
	Read a stream and parse its contents. More...

def	parse_file (self, filename)
	Read a file and parse its contents. More...

def	getvar (self, varname)
	Return the value of a variable, or None if it is unset. More...

def	str_state (self)
	Return a string description of the parser stack for debugging. More...

def	parse_lines (self, lines, filename)
	Given a multi-line string, parse the contents line-by-line. More...

def	parse_line (self, line, filename, lineno)
	Parses one line of text. More...

Public Attributes
	varhash
	The dict of variables. More...

Protected Member Functions
def	warn (self, text)
	Print a warning to the logger, if we have a logger. More...

def	applyfun (self, val, fun1, morefun)
	Applies a function to text. More...

def	from_var (self, varname, optional)
	Return the value of a variable with functions applied. More...

def	optional_var (self, varname)
	Return the value of a variable with functions applied, or '' if the variable is unset. More...

def	require_var (self, varname)
	Return the value of a variable with functions applied, raising an exception if the variable is unset. More...

def	replace_vars (self, text)
	Expand @[...] blocks in a string. More...

def	require_file (self, filename_pattern)
	Read the contents of a file and return it. More...

def	var_or_command (self, data)
	Expand one ${...} or @[...] block. More...

def	require_data (self, data)
	Expand text within an @[...] block. More...

def	active (self)
	Is the current block active?

def	top_state
	Return the top parser state without removing it. More...

def	push_state (self, state)
	Push a new state to the top of the parser state stack.

def	pop_state (self)
	Remove and return the top parser state.

def	replace_state (self, state)
	Replace the top parser state. More...

Constructor & Destructor Documentation

def produtil.atparse.ATParser.__init__	(	self,
		stream = `sys.stdout`,
		varhash = `None`,
		logger = `None`,
		max_lines = `1000000`
	)

ATParser constructor.

Parameters

stream	the output stream
varhash	a dict of variables. All values must be strings. If this is unspecified, os.environ will be used.
logger	the logging.Logger to read.
max_lines	the maximum number of lines to read

Definition at line 156 of file atparse.py.

Member Function Documentation

def produtil.atparse.ATParser.applyfun	(	self,
		val,
		fun1,
		morefun
	)

protected

Applies a function to text.

Parameters

val	the text
fun1	the function to apply
morefun	more functions to apply

Definition at line 195 of file atparse.py.

Referenced by produtil.atparse.ATParser.applyfun(), produtil.atparse.ATParser.from_var(), and produtil.atparse.ATParser.var_or_command().

def produtil.atparse.ATParser.from_var	(	self,
		varname,
		optional
	)

protected

Return the value of a variable with functions applied.

Parameters

varname	the variable name, including functions
optional	if False, raise an exception if the variable is unset. If True, return '' for unset variables.

Definition at line 215 of file atparse.py.

Referenced by produtil.atparse.ATParser.from_var(), produtil.atparse.ATParser.optional_var(), and produtil.atparse.ATParser.require_var().

def produtil.atparse.ATParser.getvar	(	self,
		varname
	)

Return the value of a variable, or None if it is unset.

Definition at line 287 of file atparse.py.

Referenced by produtil.atparse.ATParser.var_or_command().

def produtil.atparse.ATParser.infile ( self )

The current input file name.

Definition at line 188 of file atparse.py.

Referenced by produtil.atparse.ATParser.from_var().

def produtil.atparse.ATParser.max_lines ( self )

The maximum number of lines to read.

Definition at line 184 of file atparse.py.

Referenced by produtil.atparse.ATParser.parse_line().

def produtil.atparse.ATParser.optional_var	(	self,
		varname
	)

protected

Return the value of a variable with functions applied, or '' if the variable is unset.

Parameters

varname the name of the variable.

Definition at line 233 of file atparse.py.

Referenced by produtil.atparse.ATParser.parse_line().

def produtil.atparse.ATParser.parse_file	(	self,
		filename
	)

Read a file and parse its contents.

Parameters

filename the name of this file for error messages

Definition at line 270 of file atparse.py.

def produtil.atparse.ATParser.parse_line	(	self,
		line,
		filename,
		lineno
	)

Parses one line of text.

Parameters

line	the line of text.
filename	the name of the source file, for error messages
lineno	the line number within the source file, for error messages

Definition at line 462 of file atparse.py.

Referenced by produtil.atparse.ATParser.parse_file(), produtil.atparse.ATParser.parse_lines(), and produtil.atparse.ATParser.parse_stream().

def produtil.atparse.ATParser.parse_lines	(	self,
		lines,
		filename
	)

Given a multi-line string, parse the contents line-by-line.

Parameters

lines	the multi-line string
filename	the name of the file it was from, for error messages

Definition at line 453 of file atparse.py.

Referenced by produtil.atparse.ATParser.parse_line().

def produtil.atparse.ATParser.parse_stream	(	self,
		stream,
		streamname
	)

Read a stream and parse its contents.

Parameters

stream	the stream (an opened file)
streamname	a name for this stream for error messages

Definition at line 261 of file atparse.py.

def produtil.atparse.ATParser.replace_state	(	self,
		state
	)

protected

Replace the top parser state.

Parameters

state the new parser state

Definition at line 447 of file atparse.py.

Referenced by produtil.atparse.ATParser.parse_line().

def produtil.atparse.ATParser.replace_vars	(	self,
		text
	)

protected

Expand @[...] blocks in a string.

Parameters

text	the string

Returns: a new string with expansions performed

Definition at line 247 of file atparse.py.

Referenced by produtil.atparse.ATParser.parse_line(), produtil.atparse.ATParser.require_file(), and produtil.atparse.ATParser.var_or_command().

def produtil.atparse.ATParser.require_data	(	self,
		data
	)

protected

Expand text within an @[...] block.

Parameters

data	the contents of the block

Definition at line 373 of file atparse.py.

Referenced by produtil.atparse.ATParser.parse_line().

def produtil.atparse.ATParser.require_file	(	self,
		filename_pattern
	)

protected

Read the contents of a file and return it.

Parameters

filename_pattern a filename with ${} or @[] blocks in it.

Definition at line 279 of file atparse.py.

Referenced by produtil.atparse.ATParser.parse_line(), and produtil.atparse.ATParser.require_data().

def produtil.atparse.ATParser.require_var	(	self,
		varname
	)

protected

Return the value of a variable with functions applied, raising an exception if the variable is unset.

Parameters

varname the name of the variable.

Definition at line 240 of file atparse.py.

Referenced by produtil.atparse.ATParser.replace_vars(), and produtil.atparse.ATParser.var_or_command().

def produtil.atparse.ATParser.str_state ( self )

Return a string description of the parser stack for debugging.

Definition at line 390 of file atparse.py.

def produtil.atparse.ATParser.top_state	(	self,
		what = `None`
	)

protected

Return the top parser state without removing it.

Parameters

what	why the state is being examined. This is for error messages.

Definition at line 423 of file atparse.py.

Referenced by produtil.atparse.ATParser.parse_line().

def produtil.atparse.ATParser.var_or_command	(	self,
		data
	)

protected

Expand one ${...} or @[...] block.

Parameters

data	the contents of the block

Definition at line 291 of file atparse.py.

Referenced by produtil.atparse.ATParser.replace_vars(), and produtil.atparse.ATParser.require_data().

def produtil.atparse.ATParser.warn	(	self,
		text
	)

protected

Print a warning to the logger, if we have a logger.

Parameters

text	the warning text.

Definition at line 177 of file atparse.py.

Referenced by produtil.atparse.ATParser.applyfun(), and produtil.atparse.ATParser.parse_line().

Member Data Documentation

produtil.atparse.ATParser.varhash

The dict of variables.

This is NOT the dict sent to the constructor — a copy was made. That means it is safe to modify the variables all you want, even if os.environ was used.

Definition at line 164 of file atparse.py.

Referenced by produtil.atparse.ATParser.from_var(), produtil.atparse.ATParser.getvar(), and produtil.atparse.ATParser.var_or_command().

The documentation for this class was generated from the following file:

/mnt/pan2/projects/hwrfv3/Samuel.Trahan/trunk/ush/produtil/atparse.py

Detailed Description

Public Member Functions

Public Attributes

Protected Member Functions

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation