ONLY DO PART $3($Code Below$)$

class AdvancedCalculator:

$\text{'}\text{'}\text{'}$

$>>>$ C $=$ AdvancedCalculator$()$

$>>>$ C$.$states $==\{\}$

True

$>>>$ C$.$setExpression$(\text{'}$a $=5$;b $=7+$ a;a $=7$;c $=$ a $+$ b;c $=$ a $*0$;return c$\text{'})$

$>>>$ C$.$calculateExpressions$()==\{\text{'}$a $=5\text{'}$: $\{\text{'}$a$\text{'}$: $5\mathrm{.}0\},\text{'}$b $=7+$ a$\text{'}$: $\{\text{'}$a$\text{'}$: $5\mathrm{.}0,\text{'}$b$\text{'}$: $12\mathrm{.}0\},\text{'}$a $=7\text{'}$: $\{\text{'}$a$\text{'}$: $7\mathrm{.}0,\text{'}$b$\text{'}$: $12\mathrm{.}0\},\text{'}$c $=$ a $+$ b$\text{'}$: $\{\text{'}$a$\text{'}$: $7\mathrm{.}0,\text{'}$b$\text{'}$: $12\mathrm{.}0,\text{'}$c$\text{'}$: $19\mathrm{.}0\},\text{'}$c $=$ a $*0\text{'}$: $\{\text{'}$a$\text{'}$: $7\mathrm{.}0,\text{'}$b$\text{'}$: $12\mathrm{.}0,\text{'}$c$\text{'}$: $0\mathrm{.}0\},\text{'}\_$return$\_\text{'}$: $0\mathrm{.}0\}$

True

$>>>$ C$.$states $==\{\text{'}$a$\text{'}$: $7\mathrm{.}0,\text{'}$b$\text{'}$: $12\mathrm{.}0,\text{'}$c$\text{'}$: $0\mathrm{.}0\}$

True

$>>>$ C$.$setExpression$(\text{'}$x$1=5$;x$2=7[$ x$1-1]$;x$1=$ x$2-$ x$1$;return x$2+$ x$1^3\text{'})$

$>>>$ C$.$states $==\{\}$

True

$>>>$ C$.$calculateExpressions$()==\{\text{'}$x$1=5\text{'}$: $\{\text{'}$x$1\text{'}$: $5\mathrm{.}0\},\text{'}$x$2=7[$ x$1-1]\text{'}$: $\{\text{'}$x$1\text{'}$: $5\mathrm{.}0,\text{'}$x$2\text{'}$: $28\mathrm{.}0\},\text{'}$x$1=$ x$2-$ x$1\text{'}$: $\{\text{'}$x$1\text{'}$: $23\mathrm{.}0,\text{'}$x$2\text{'}$: $28\mathrm{.}0\},\text{'}\_$return$\_\text{'}$: $12195\mathrm{.}0\}$

True

$>>>$ print$($C$.$calculateExpressions$())$

$\{\text{'}$x$1=5\text{'}$: $\{\text{'}$x$1\text{'}$: $5\mathrm{.}0\},\text{'}$x$2=7[$ x$1-1]\text{'}$: $\{\text{'}$x$1\text{'}$: $5\mathrm{.}0,\text{'}$x$2\text{'}$: $28\mathrm{.}0\},\text{'}$x$1=$ x$2-$ x$1\text{'}$: $\{\text{'}$x$1\text{'}$: $23\mathrm{.}0,\text{'}$x$2\text{'}$: $28\mathrm{.}0\},\text{'}\_$return$\_\text{'}$: $12195\mathrm{.}0\}$

$>>>$ C$.$states $==\{\text{'}$x$1\text{'}$: $23\mathrm{.}0,\text{'}$x$2\text{'}$: $28\mathrm{.}0\}$

True

$>>>$ C$.$setExpression$(\text{'}$x$1=5*5+97$;x$2=7*\{$ x$1/2\}$;x$1=$ x$2*7/$ x$1$;return x$1($ x$2-5)\text{'})$

$>>>$ C$.$calculateExpressions$()==\{\text{'}$x$1=5*5+97\text{'}$: $\{\text{'}$x$1\text{'}$: $122\mathrm{.}0\},\text{'}$x$2=7*\{$ x$1/2\}\text{'}$: $\{\text{'}$x$1\text{'}$: $122\mathrm{.}0,\text{'}$x$2\text{'}$: $427\mathrm{.}0\},\text{'}$x$1=$ x$2*7/$ x$1\text{'}$: $\{\text{'}$x$1\text{'}$: $24\mathrm{.}5,\text{'}$x$2\text{'}$: $427\mathrm{.}0\},\text{'}\_$return$\_\text{'}$: $10339\mathrm{.}0\}$

True

$>>>$ C$.$states $==\{\text{'}$x$1\text{'}$: $24\mathrm{.}5,\text{'}$x$2\text{'}$: $427\mathrm{.}0\}$

True

$>>>$ C$.$setExpression$(\text{'}$A $=1$;B $=$ A $+9$;C $=$ A $+$ B;A $=20$;D $=$ A $+$ B $+$ C;return D $-$ A$\text{'})$

$>>>$ C$.$calculateExpressions$()==\{\text{'}$A $=1\text{'}$: $\{\text{'}$A$\text{'}$: $1\mathrm{.}0\},\text{'}$B $=$ A $+9\text{'}$: $\{\text{'}$A$\text{'}$: $1\mathrm{.}0,\text{'}$B$\text{'}$: $10\mathrm{.}0\},\text{'}$C $=$ A $+$ B$\text{'}$: $\{\text{'}$A$\text{'}$: $1\mathrm{.}0,\text{'}$B$\text{'}$: $10\mathrm{.}0,\text{'}$C$\text{'}$: $11\mathrm{.}0\},\text{'}$A $=20\text{'}$: $\{\text{'}$A$\text{'}$: $20\mathrm{.}0,\text{'}$B$\text{'}$: $10\mathrm{.}0,\text{'}$C$\text{'}$: $11\mathrm{.}0\},\text{'}$D $=$ A $+$ B $+$ C$\text{'}$: $\{\text{'}$A$\text{'}$: $20\mathrm{.}0,\text{'}$B$\text{'}$: $10\mathrm{.}0,\text{'}$C$\text{'}$: $11\mathrm{.}0,\text{'}$D$\text{'}$: $41\mathrm{.}0\},\text{'}\_$return$\_\text{'}$: $21\mathrm{.}0\}$

True

$>>>$ C$.$states $==\{\text{'}$A$\text{'}$: $20\mathrm{.}0,\text{'}$B$\text{'}$: $10\mathrm{.}0,\text{'}$C$\text{'}$: $11\mathrm{.}0,\text{'}$D$\text{'}$: $41\mathrm{.}0\}$

True

$>>>$ C$.$setExpression$(\text{'}$A $=1$;B $=$ A $+9$;$2$C $=$ A $+$ B;A $=20$;D $=$ A $+$ B $+$ C;return D $+$ A$\text{'})$

$>>>$ C$.$calculateExpressions$()$ is None

True

$>>>$ C$.$states $==\{\}$

True

$\text{'}\text{'}\text{'}$

def $\_\_$init$\_\_($self$)$:

self.expressions $=\text{'}\text{'}$

self.states $=\{\}$

def setExpression$($self$,$ expression$)$:

self.expressions $=$ expression

self.states $=\{\}$

def $\_$isVariable$($self$,$ word$)$:

$\text{'}\text{'}\text{'}$

$>>>$ C $=$ AdvancedCalculator$()$

$>>>$ C$.\_$isVariable$(\text{'}$volume$\text{'})$

True

$>>>$ C$.\_$isVariable$(\text{'}4$volume'$)$

False

$>>>$ C$.\_$isVariable$(\text{'}$volume$2\text{'})$

True

$>>>$ C$.\_$isVariable$(\text{'}$vol$\%2\text{'})$

False

$\text{'}\text{'}\text{'}$

# YOUR CODE STARTS HERE

pass

def $\_$replaceVariables$($self$,$ expr$)$:

$\text{'}\text{'}\text{'}$

$>>>$ C $=$ AdvancedCalculator$()$

$>>>$ C$.$states $=\{\text{'}$x$1\text{'}$: $23\mathrm{.}0,\text{'}$x$2\text{'}$: $28\mathrm{.}0\}$

$>>>$ C$.\_$replaceVariables$(\text{'}1\text{'})$

$\text{'}1\text{'}$

$>>>$ C$.\_$replaceVariables$(\text{'}105+$ x$\text{'})$

$>>>$ C$.\_$replaceVariables$(\text{'}7($ x$1-1)\text{'})$

$\text{'}7(23\mathrm{.}0-1)\text{'}$

$>>>$ C$.\_$replaceVariables$(\text{'}$x$2-$ x$1\text{'})$

$\text{'}28\mathrm{.}0-23\mathrm{.}0\text{'}$

$\text{'}\text{'}\text{'}$

# YOUR CODE STARTS HERE

pass

def calculateExpressions$($self$)$:

self.states $=\{\}$

calcObj $=$ Calculator$()$ # method must use calcObj to compute each expression

# YOUR CODE STARTS HERE

pass