How can I convert the grid of symbols into a list of strings
Question:
the input for the to_strings function is the grid so whatever that the grid shows should be converted into a list of strings where
input example :
A B C
1 . . .
2 . @ .
3 . O .
output example :
['...', '.@.', '.O.']
True
first Issue is in this particular function as it does not provide the expected output
def to_strings(self):
from itertools import chain
m_list_tostring=[]
for i in range(len(self.grid)):
x=list(chain.from_iterable(self.grid))
m_list_tostring = ''.join([str(x) for self.grid, i in enumerate(x)]) # to convert the list of characters into a string
print(x)
return str(x)
I also have an issue with a particular assertion error that needs to be raised where it checks for invalid inputs (the letter x should indicate the row coordinate of the invalid row) where "invalid character in row x"
the code shown below is what i came up with however it gives an error
assert i == self.grid[i], "invalid character in row "+i
I need to add an additional optional argument from_strings to the constructor. If it’s present, this argument must be a list of strings where each string gives a row of the board with the character encoding used in the __str__() method, but without the spaces and the coordinate letters.
And also a method to_strings(self) that gives a representation of the board as a list of strings in the same format as that accepted by the __init__() method from the from_strings.
How can i get the expected output ?
from string import ascii_uppercase as letters
class Board:
#Dictionary created for the colours and the respected symbols
points = {'E': '.', 'B': '@', 'W': 'O'}
#Constructor
def __init__(self,size=19,from_strings=None):
assert 2 <= size <= 26, "Illegal board size: must be between 2 and 26."
assert type(from_strings) is list,"input is not a list"
assert len(from_strings)==size, "length of input list does not match size"
for i in from_strings:
assert type(i)==str, "row "+i+" is not a string"
assert len(i)==size,"length of row "+i+" does not match size"
#assert i== b[i], "invalid character in row "+i
self.size = size
self.grid = [['E'] * size for _ in range(size)]
self.from_strings = [] if from_strings is None else from_strings
def get_size(self): #Returns the size of the grid created by the constructor
return self.size
def __str__(self): #creating the grid
padding=' ' #Creating a variable with a space assigned so that it acts as a padding to the rows that have a single digit
heading = ' ' + ' '.join(letters[:self.size]) #Alphabetical heading is created
lines = [heading] #adding the alphabetical heading into a list named lines to which the rows will be added later
for r, row in enumerate(self.grid):
if len(self.grid)<10: #for the grid with a size less than 10 to add the space to the start of the row for the single digits to be aligned
line = " " +f'{self.size - r} ' + ' '.join(self.points[x] for x in row)
lines.append(line)
else: #for the grids that are larger than 9
if r>9: #for rows 1 to 9 the single digits are aligned according to the first digit from the right of the two digit rows
line =f'{self.size - r} ' + ' '.join(self.points[x] for x in row)
line=padding+line #adding the space using the variable padding to the row created
lines.append(line) #adding the row to the list of rows
else: #for the rows 10 onwards - as there is no requirement to add a padding it is not added here
line = f'{self.size - r} ' + ' '.join(self.points[x] for x in row)#creation of the row
lines.append(line) #adding the newly created row to the list of rows
return 'n'.join(lines)
def _to_row_and_column(self, coords):
# destructure coordinates like "B2" to "B" and 2
alpha, num = coords
colnum = ord(alpha) - ord('A') + 1
rownum = self.size - int(num) + 1
assert 1 <= rownum <= self.size,"row out of range"
assert 1 <= colnum <= self.size,'column out of range'
return rownum, colnum
def set_colour(self, coords, colour_name):
rownum, colnum = self._to_row_and_column(coords)
assert len(coords)==2 or len(coords)==3, "invalid coordinates"
assert colour_name in self.points,"invalid colour name"
self.grid[rownum - 1][colnum - 1] = colour_name
def get_colour(self, coords):
rownum, colnum = self._to_row_and_column(coords)
return self.grid[rownum - 1][colnum - 1]
def to_strings(self):
from itertools import chain
m_list_tostring=[]
for i in range(len(self.grid)):
x=list(chain.from_iterable(self.grid))
m_list_tostring = ''.join([str(x) for self.grid, i in enumerate(x)]) # to convert the list of characters into a string
print(x)
return x
b =Board(3, ["O.O", ".@.", "@O."])
print(b)
print(b.to_strings())
c =Board(b.get_size(), b.to_strings())
print(str(b) == str(c))
for now my code is as such
however I’m not getting the expected output which is shown below
A B C
3 O . O
2 . @ .
1 @ O .
['O.O', '.@.', '@O.']
True
so the output i got is from my code is :
['E', 'E', 'E', 'E', 'E', 'E', 'E', 'W', 'E']
Answers:
I executed the code myself and make some changes to get closer to your desired answer.
First ,i don’t know exactly what this line do , neither what b stands for , so i removed it:
assert i== b[i], "invalid character in row "+i.
Then i looked to _str_ method, that is the method that do the class printing, when you call:
print(b)
It doesn’t have any mentions to self.from_strings
Basically in each line , respecting formatting style for the size the of the grid, it is print the correspondent character of the letter you defined in points dictionary as we can see here :
join(self.points[x] for x in row)
Since the points and grid is like this :
self.grid = [['E'] * size for _ in range(size)]
points = {'E': '.', 'B': '@', 'W': 'O'}
It gives the output:
A B C
3 . . .
2 . . .
1 . . .
Assuming that you when from_strings parameter you want that class print that way , i used conditional to use this
def __str__(self): #creating the grid
padding=' ' #Creating a variable with a space assigned so that it acts as a padding to the rows that have a single digit
heading = ' ' + ' '.join(letters[:self.size]) #Alphabetical heading is created
lines = [heading] #adding the alphabetical heading into a list named lines to which the rows will be added later
for r, row in enumerate(self.grid):
if len(self.grid)<10: #for the grid with a size less than 10 to add the space to the start of the row for the single digits to be aligned
if (self.from_strings):
line = " " +f'{self.size - r} ' + ' '.join(self.from_strings[r])
else:
line = " " +f'{self.size - r} ' + ' '.join(self.points[x] for x in row)
lines.append(line)
else: #for the grids that are larger than 9
if r>9: #for rows 1 to 9 the single digits are aligned according to the first digit from the right of the two digit rows
if (self.from_strings):
line = f'{self.size - r} ' + ' '.join(self.from_strings[r])
else:
line =f'{self.size - r} ' + ' '.join(self.points[x] for x in row)
line=padding+line #adding the space using the variable padding to the row created
lines.append(line) #adding the row to the list of rows
else: #for the rows 10 onwards - as there is no requirement to add a padding it is not added here
if (self.from_strings):
line = f'{self.size - r} ' + ' '.join(self.from_strings[r])
else:
line = f'{self.size - r} ' + ' '.join(self.points[x] for x in row)#creation of the row
lines.append(line) #adding the newly created row to the list of rows
return 'n'.join(lines)
And use the same logic to to_strings method :
def to_strings(self):
padding=' '
lines = []
for r, row in enumerate(self.grid):
if self.from_strings :
lines.append(''.join(self.from_strings[r]))
else :
lines.append(''.join(self.points[x] for x in row))
return lines
The output is shown like this :
A B C
3 O . O
2 . @ .
1 @ O .
['O.O', '.@.', '@O.']
True
the input for the to_strings function is the grid so whatever that the grid shows should be converted into a list of strings where
input example :
A B C
1 . . .
2 . @ .
3 . O .
output example :
['...', '.@.', '.O.']
True
first Issue is in this particular function as it does not provide the expected output
def to_strings(self):
from itertools import chain
m_list_tostring=[]
for i in range(len(self.grid)):
x=list(chain.from_iterable(self.grid))
m_list_tostring = ''.join([str(x) for self.grid, i in enumerate(x)]) # to convert the list of characters into a string
print(x)
return str(x)
I also have an issue with a particular assertion error that needs to be raised where it checks for invalid inputs (the letter x should indicate the row coordinate of the invalid row) where "invalid character in row x"
the code shown below is what i came up with however it gives an error
assert i == self.grid[i], "invalid character in row "+i
I need to add an additional optional argument from_strings to the constructor. If it’s present, this argument must be a list of strings where each string gives a row of the board with the character encoding used in the __str__() method, but without the spaces and the coordinate letters.
And also a method to_strings(self) that gives a representation of the board as a list of strings in the same format as that accepted by the __init__() method from the from_strings.
How can i get the expected output ?
from string import ascii_uppercase as letters
class Board:
#Dictionary created for the colours and the respected symbols
points = {'E': '.', 'B': '@', 'W': 'O'}
#Constructor
def __init__(self,size=19,from_strings=None):
assert 2 <= size <= 26, "Illegal board size: must be between 2 and 26."
assert type(from_strings) is list,"input is not a list"
assert len(from_strings)==size, "length of input list does not match size"
for i in from_strings:
assert type(i)==str, "row "+i+" is not a string"
assert len(i)==size,"length of row "+i+" does not match size"
#assert i== b[i], "invalid character in row "+i
self.size = size
self.grid = [['E'] * size for _ in range(size)]
self.from_strings = [] if from_strings is None else from_strings
def get_size(self): #Returns the size of the grid created by the constructor
return self.size
def __str__(self): #creating the grid
padding=' ' #Creating a variable with a space assigned so that it acts as a padding to the rows that have a single digit
heading = ' ' + ' '.join(letters[:self.size]) #Alphabetical heading is created
lines = [heading] #adding the alphabetical heading into a list named lines to which the rows will be added later
for r, row in enumerate(self.grid):
if len(self.grid)<10: #for the grid with a size less than 10 to add the space to the start of the row for the single digits to be aligned
line = " " +f'{self.size - r} ' + ' '.join(self.points[x] for x in row)
lines.append(line)
else: #for the grids that are larger than 9
if r>9: #for rows 1 to 9 the single digits are aligned according to the first digit from the right of the two digit rows
line =f'{self.size - r} ' + ' '.join(self.points[x] for x in row)
line=padding+line #adding the space using the variable padding to the row created
lines.append(line) #adding the row to the list of rows
else: #for the rows 10 onwards - as there is no requirement to add a padding it is not added here
line = f'{self.size - r} ' + ' '.join(self.points[x] for x in row)#creation of the row
lines.append(line) #adding the newly created row to the list of rows
return 'n'.join(lines)
def _to_row_and_column(self, coords):
# destructure coordinates like "B2" to "B" and 2
alpha, num = coords
colnum = ord(alpha) - ord('A') + 1
rownum = self.size - int(num) + 1
assert 1 <= rownum <= self.size,"row out of range"
assert 1 <= colnum <= self.size,'column out of range'
return rownum, colnum
def set_colour(self, coords, colour_name):
rownum, colnum = self._to_row_and_column(coords)
assert len(coords)==2 or len(coords)==3, "invalid coordinates"
assert colour_name in self.points,"invalid colour name"
self.grid[rownum - 1][colnum - 1] = colour_name
def get_colour(self, coords):
rownum, colnum = self._to_row_and_column(coords)
return self.grid[rownum - 1][colnum - 1]
def to_strings(self):
from itertools import chain
m_list_tostring=[]
for i in range(len(self.grid)):
x=list(chain.from_iterable(self.grid))
m_list_tostring = ''.join([str(x) for self.grid, i in enumerate(x)]) # to convert the list of characters into a string
print(x)
return x
b =Board(3, ["O.O", ".@.", "@O."])
print(b)
print(b.to_strings())
c =Board(b.get_size(), b.to_strings())
print(str(b) == str(c))
for now my code is as such
however I’m not getting the expected output which is shown below
A B C
3 O . O
2 . @ .
1 @ O .
['O.O', '.@.', '@O.']
True
so the output i got is from my code is :
['E', 'E', 'E', 'E', 'E', 'E', 'E', 'W', 'E']
I executed the code myself and make some changes to get closer to your desired answer.
First ,i don’t know exactly what this line do , neither what b stands for , so i removed it:
assert i== b[i], "invalid character in row "+i.
Then i looked to _str_ method, that is the method that do the class printing, when you call:
print(b)
It doesn’t have any mentions to self.from_strings
Basically in each line , respecting formatting style for the size the of the grid, it is print the correspondent character of the letter you defined in points dictionary as we can see here :
join(self.points[x] for x in row)
Since the points and grid is like this :
self.grid = [['E'] * size for _ in range(size)]
points = {'E': '.', 'B': '@', 'W': 'O'}
It gives the output:
A B C
3 . . .
2 . . .
1 . . .
Assuming that you when from_strings parameter you want that class print that way , i used conditional to use this
def __str__(self): #creating the grid
padding=' ' #Creating a variable with a space assigned so that it acts as a padding to the rows that have a single digit
heading = ' ' + ' '.join(letters[:self.size]) #Alphabetical heading is created
lines = [heading] #adding the alphabetical heading into a list named lines to which the rows will be added later
for r, row in enumerate(self.grid):
if len(self.grid)<10: #for the grid with a size less than 10 to add the space to the start of the row for the single digits to be aligned
if (self.from_strings):
line = " " +f'{self.size - r} ' + ' '.join(self.from_strings[r])
else:
line = " " +f'{self.size - r} ' + ' '.join(self.points[x] for x in row)
lines.append(line)
else: #for the grids that are larger than 9
if r>9: #for rows 1 to 9 the single digits are aligned according to the first digit from the right of the two digit rows
if (self.from_strings):
line = f'{self.size - r} ' + ' '.join(self.from_strings[r])
else:
line =f'{self.size - r} ' + ' '.join(self.points[x] for x in row)
line=padding+line #adding the space using the variable padding to the row created
lines.append(line) #adding the row to the list of rows
else: #for the rows 10 onwards - as there is no requirement to add a padding it is not added here
if (self.from_strings):
line = f'{self.size - r} ' + ' '.join(self.from_strings[r])
else:
line = f'{self.size - r} ' + ' '.join(self.points[x] for x in row)#creation of the row
lines.append(line) #adding the newly created row to the list of rows
return 'n'.join(lines)
And use the same logic to to_strings method :
def to_strings(self):
padding=' '
lines = []
for r, row in enumerate(self.grid):
if self.from_strings :
lines.append(''.join(self.from_strings[r]))
else :
lines.append(''.join(self.points[x] for x in row))
return lines
The output is shown like this :
A B C
3 O . O
2 . @ .
1 @ O .
['O.O', '.@.', '@O.']
True