Write and test the following function that uses a Stack:

def stack$\_$maze$($maze$)$:

$"""$

Solves a maze using Depth$-$First search.

Use: path $=$ stack$\_$maze $($maze$)$

Parameters:

maze $-$ dictionary of points in a maze, where each point

represents a corridor end or a branch. Dictionary

keys are the name of the point followed by a list of

branches, if any. First point is named 'start', exit

is named $\text{'}x\text{'}($dict$)$

Returns:

path $-$ list of points visited before the exit is reached,

None if there is no exit $($list of str$)$

Add the function to a PyDev module named functions. py$.$ Test it from

t$07.$py$.$

See Stacks $-$ Solving a Maze

This maze can be represented by a Python dictionary:

maze $-\{\text{'}$Start$\text{'}$: $[\text{'}$A$\text{'}],\text{'}$A$\text{'}$: $[\text{'}$B$\text{'},\text{'}$C$\text{'}],\text{'}$B$\text{'}$: $[],\text{'}$C$\text{'}$:$[\text{'}$D$\text{'},\text{'}$E$\text{'}],$

$\text{'}D\text{'}$: $[],\text{'}E\text{'}$: $[\text{'}F\text{'},\text{'}X\text{'}],\text{'}F\text{'}$:$[\text{'}G\text{'},\text{'}H\text{'}],\text{'}G\text{'}$:$[],\text{'}H\text{'}$:$[]$

Each entry in these Python dictionaries consists of two parts:

ker: value

so for the sample maze, it's 'Start' entry has key: 'Start' and value: $[\text{'}$A$\text{'}].$

Since dictionaries use a key rather than an index, to extract a value from a dictionary use the syntax:

value $=$ maze $[$key