imported>Unknown at 05:29, 7 February 2021

2021-02-07T05:29:29Z

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== Python version ==
* 개발자 : 나휘동
''ExpressionConverter.py''
class ExpressionConverter:
def __init__(self, aExpression = ''):
self.expression = aExpression
self.precedence = {'*':13, '+':12, '-':12, '/':13}
self.list = []

def getPrecedence(self, aToken):
return self.precedence[aToken]

def isOperator(self, aToken):
if aToken in self.precedence:
return True
return False
def getConvertedExpression(self):
expression = ''
for l in self.list:
expression += l
return expression

def putToken(self, aToken):
if self.isOperator(aToken):
self.putOperator(aToken)
else:
self.list.append(aToken)

def putOperator(self, aOperator):
if self.isOperator(self.list[0]) and \
self.precedence[self.list[0]] < self.precedence[aOperator]:
self.list.insert(-1, aOperator)
else:
self.list.insert(0, aOperator)

def convertInfixToPrefix(self):
for e in self.expression:
self.putToken(e)

#########################################################################

import unittest

class ExpressionConverterTestCase(unittest.TestCase):
def testGetPrecedence(self):
e = ExpressionConverter()

token = '*'
self.assertEqual(e.getPrecedence(token), 13)
token = '+'
self.assertEqual(e.getPrecedence(token), 12)
def testIsOperator(self):
e = ExpressionConverter()

token = 'a'
self.assertEqual(e.isOperator(token), False)
token = '+'
self.assertEqual(e.isOperator(token), True)

def testGetConvertedExpression(self):
e = ExpressionConverter()
e.list = '+a'
self.assertEqual( e.getConvertedExpression(), '+a')

def testPutToken(self):
e = ExpressionConverter()

token = 'a'
e.putToken(token)
token = '+'
e.putToken(token)
self.assertEqual( e.getConvertedExpression(), '+a')

token = 'b'
e.putToken(token)
self.assertEqual( e.getConvertedExpression(), '+ab')

def testPutOperator(self):
e = ExpressionConverter()
token = 'a'
e.putToken(token)
token = '+'
e.putToken(token)
token = 'b'
e.putToken(token)

token = '*'
e.putOperator(token)
self.assertEqual( e.getConvertedExpression(), '+a*b')

def testConvertInfixToPrefix(self):
expression = 'a+b*c'
e = ExpressionConverter(expression)

e.convertInfixToPrefix()
self.assertEqual( e.getConvertedExpression(), '+a*bc')

expression = 'a+b*c/x'
e = ExpressionConverter(expression)

e.convertInfixToPrefix()
self.assertEqual( e.getConvertedExpression(), '+a*b/cx')
if __name__ == '__main__':
unittest.main()
----
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몸짱프로젝트/InfixToPrefix - Revision history

imported>Unknown at 05:29, 7 February 2021