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Diffstat (limited to 'examples/excel_expr.py')
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diff --git a/examples/excel_expr.py b/examples/excel_expr.py new file mode 100644 index 0000000..db19f3c --- /dev/null +++ b/examples/excel_expr.py @@ -0,0 +1,93 @@ +# excelExpr.py +# +# Copyright 2010, Paul McGuire +# +# A partial implementation of a parser of Excel formula expressions. +# +import pyparsing as pp +ppc = pp.common + +pp.ParserElement.enablePackrat() + +EQ, LPAR, RPAR, COLON, COMMA = pp.Suppress.using_each("=():,") +EXCL, DOLLAR = pp.Literal.using_each("!$") +sheetRef = pp.Word(pp.alphas, pp.alphanums) | pp.QuotedString("'", escQuote="''") +colRef = pp.Opt(DOLLAR) + pp.Word(pp.alphas, max=2) +rowRef = pp.Opt(DOLLAR) + pp.Word(pp.nums) +cellRef = pp.Combine( + pp.Group(pp.Opt(sheetRef + EXCL)("sheet") + colRef("col") + rowRef("row")) +) + +cellRange = ( + pp.Group(cellRef("start") + COLON + cellRef("end"))("range") + | cellRef + | pp.Word(pp.alphas, pp.alphanums) +) + +expr = pp.Forward() + +COMPARISON_OP = pp.one_of("< = > >= <= != <>") +condExpr = expr + COMPARISON_OP + expr + +ifFunc = ( + pp.CaselessKeyword("if") + - LPAR + + pp.Group(condExpr)("condition") + + COMMA + + pp.Group(expr)("if_true") + + COMMA + + pp.Group(expr)("if_false") + + RPAR +) + + +def stat_function(name): + return pp.Group(pp.CaselessKeyword(name) + pp.Group(LPAR + pp.DelimitedList(expr) + RPAR)) + + +sumFunc = stat_function("sum") +minFunc = stat_function("min") +maxFunc = stat_function("max") +aveFunc = stat_function("ave") +funcCall = ifFunc | sumFunc | minFunc | maxFunc | aveFunc + +multOp = pp.one_of("* /") +addOp = pp.one_of("+ -") +numericLiteral = ppc.number +operand = numericLiteral | funcCall | cellRange | cellRef +arithExpr = pp.infix_notation( + operand, + [ + (multOp, 2, pp.OpAssoc.LEFT), + (addOp, 2, pp.OpAssoc.LEFT), + ], +) + +textOperand = pp.dblQuotedString | cellRef +textExpr = pp.infix_notation( + textOperand, + [ + ("&", 2, pp.OpAssoc.LEFT), + ], +) + +expr <<= arithExpr | textExpr + + +def main(): + success, report = (EQ + expr).run_tests( + """\ + =3*A7+5 + =3*Sheet1!$A$7+5 + =3*'Sheet 1'!$A$7+5 + =3*'O''Reilly''s sheet'!$A$7+5 + =if(Sum(A1:A25)>42,Min(B1:B25),if(Sum(C1:C25)>3.14, (Min(C1:C25)+3)*18,Max(B1:B25))) + =sum(a1:a25,10,min(b1,c2,d3)) + =if("T"&a2="TTime", "Ready", "Not ready") + """ + ) + assert success + + +if __name__ == '__main__': + main()
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