Have Geek Brain

Some help with some Python code

Can anyone tell me why num_chars and num_rows should be the same?

from ctypes import *

num_chars = 8
num_rows = 8
num_cols = 6

buffer = create_string_buffer (num_chars*num_rows*num_cols+num_chars)

for char in range(num_chars):
        for row in range(num_rows):
                for col in range(num_cols):
                        if char == num_chars-1 and col == num_cols-1:
                                buffer[row*num_rows*num_cols+char*num_cols+col+row] = '|'
                                buffer[row*num_rows*num_cols+char*num_cols+col+row+1] = '\n'
                        elif col == num_cols-1:
                                buffer[row*num_rows*num_cols+char*num_cols+col+row] = '|'
                        else:
                                buffer[row*num_rows*num_cols+char*num_cols+col+row] = ('.', '*')[char>row]

print buffer.value

Exit

.....|*****|*****|*****|*****|*****|*****|*****|
.....|.....|*****|*****|*****|*****|*****|*****|
.....|.....|.....|*****|*****|*****|*****|*****|
.....|.....|.....|.....|*****|*****|*****|*****|
.....|.....|.....|.....|.....|*****|*****|*****|
.....|.....|.....|.....|.....|.....|*****|*****|
.....|.....|.....|.....|.....|.....|.....|*****|
.....|.....|.....|.....|.....|.....|.....|.....|

And now change num_chars to 15.

.....|*****|*****|*****|*****|*****|*****|*****|*****|*****|*****|*****|*****|*****|*****|
*****|*****|*****|*****|*****|*****|*****|*****|
*****|*****|*****|*****|*****|*****|*****|*****|
*****|*****|*****|*****|*****|*****|*****|*****|
*****|*****|*****|*****|*****|*****|*****|*****|
*****|*****|*****|*****|*****|*****|*****|*****|
*****|*****|*****|*****|*****|*****|*****|*****|
.....|*****|*****|*****|*****|*****|*****|*****|
-3


a source to share


2 answers


You said you were using ctypes because you want to use a mutable char buffer for that. But you can get the desired result from a list comprehension.

num_chars = 5
num_rows = 8
empty = ['.' * num_chars]
full = ['*' * num_chars]
print '\n'.join(
    '|'.join(empty * (i + 1) + (num_rows - i - 1) * full)
    for i in xrange(num_rows)
)

.....|*****|*****|*****|*****|*****|*****|*****
.....|.....|*****|*****|*****|*****|*****|*****
.....|.....|.....|*****|*****|*****|*****|*****
.....|.....|.....|.....|*****|*****|*****|*****
.....|.....|.....|.....|.....|*****|*****|*****
.....|.....|.....|.....|.....|.....|*****|*****
.....|.....|.....|.....|.....|.....|.....|*****
.....|.....|.....|.....|.....|.....|.....|.....

EDIT



I'll show you how you can use list methods to draw any char bitmaps you want to draw. The idea is simple. Create a boolean array with True where you want to print the character and False otherwise. And just use the "or" trick to print the correct character. In this example, a checkerboard will be built. You can use the same concept to draw any shape.

rows = 5
cols = 6
char = '#'
empty = '.'
bitmap = [[ (i + j)%2 == 0 for i in xrange(cols)] for j in xrange(rows)]
print '\n'.join(
    '|'.join(bitmap[j][i] * char or empty for i in xrange(cols))
    for j in xrange(rows)
)
+5


a source


There we go. I had rownum_rows instead of rownum_chars I needed Dr Pepper. And by the way, this was not homework. This is for an LCD project.



num_chars = 10
num_rows = 8
num_cols = 6

buffer = create_string_buffer (num_chars*num_rows*num_cols+num_chars)

for char in range(num_chars):
        for row in range(num_rows):
                for col in range(num_cols):
                        if char == num_chars-1 and col == num_cols-1:
                                buffer[row*num_chars*num_cols+char*num_cols+col+row] = '|'
                                buffer[row*num_chars*num_cols+char*num_cols+col+row+1] = '\n'
                        elif col == num_cols-1:
                                buffer[row*num_chars*num_cols+char*num_cols+col+row] = '|'
                        else:
                                buffer[row*num_chars*num_cols+char*num_cols+col+row] = ('.', '*')[char>row]

print repr(buffer.raw)
print buffer.value
+1


a source






More articles:


All Articles