Why are these for loops running incredibly slow in python?
Question:
I’m working on a short programme which will create a 2d array for the Tabula Recta. However, I am finding it is running incredibly slow, especially the further down the for loop I get. What is the reason for this, as I’ve never had a for loop run so slow before, which is especially confusing as I don’t think any of the operations are that expensive.
The code looks like this:
def initTabulaRecta(alphabet = "abcdefghijklmnopqrstuvwxyz"):
tabularecta = [[]]
for let in " "+alphabet.upper(): tabularecta[0].append(let) # Adds the top layer to the table
for i in range(len(alphabet)):
tabularecta.append([alphabet.upper()[0]]) # Adds the side layer to the table
for let in alphabet: tabularecta[i+1].append(let) # Fills in each letter for that row
alphabet = alphabet[:len(alphabet)-1] + alphabet[1:] # Changes order of alphabet, for next row
Answers:
It looks like the code is running slowly because of the way the inner for loop is being implemented. Specifically, the line alphabet = alphabet[:len(alphabet)-1] + alphabet[1:] is causing the loop to run slower over time because it is changing the length of the alphabet string on each iteration of the loop. This means that the loop has to do more work on each subsequent iteration, which can make it run slower and slower.
One way to improve the performance of this code would be to use a different approach for the inner for loop. For example, instead of changing the alphabet string on each iteration of the loop, you could create a new string that contains the letters of the alphabet in the correct order, and then use that string to fill in the values for each row of the tabularecta array. This would allow the loop to run at a consistent speed, rather than getting slower over time.
Another way to improve the performance of this code would be to use a different data structure for the tabularecta array. A 2D array is not the most efficient data structure for this kind of problem, and using a different data structure (such as a dictionary or a list of lists) could potentially make the code run faster.
Overall, there are a few different ways you could improve the performance of this code, but the key is to avoid changing the length of the alphabet string on each iteration of the inner for loop. Using a different data structure and/or a different approach for the inner for loop should help to make the code run more efficiently.
I’m working on a short programme which will create a 2d array for the Tabula Recta. However, I am finding it is running incredibly slow, especially the further down the for loop I get. What is the reason for this, as I’ve never had a for loop run so slow before, which is especially confusing as I don’t think any of the operations are that expensive.
The code looks like this:
def initTabulaRecta(alphabet = "abcdefghijklmnopqrstuvwxyz"):
tabularecta = [[]]
for let in " "+alphabet.upper(): tabularecta[0].append(let) # Adds the top layer to the table
for i in range(len(alphabet)):
tabularecta.append([alphabet.upper()[0]]) # Adds the side layer to the table
for let in alphabet: tabularecta[i+1].append(let) # Fills in each letter for that row
alphabet = alphabet[:len(alphabet)-1] + alphabet[1:] # Changes order of alphabet, for next row
It looks like the code is running slowly because of the way the inner for loop is being implemented. Specifically, the line alphabet = alphabet[:len(alphabet)-1] + alphabet[1:] is causing the loop to run slower over time because it is changing the length of the alphabet string on each iteration of the loop. This means that the loop has to do more work on each subsequent iteration, which can make it run slower and slower.
One way to improve the performance of this code would be to use a different approach for the inner for loop. For example, instead of changing the alphabet string on each iteration of the loop, you could create a new string that contains the letters of the alphabet in the correct order, and then use that string to fill in the values for each row of the tabularecta array. This would allow the loop to run at a consistent speed, rather than getting slower over time.
Another way to improve the performance of this code would be to use a different data structure for the tabularecta array. A 2D array is not the most efficient data structure for this kind of problem, and using a different data structure (such as a dictionary or a list of lists) could potentially make the code run faster.
Overall, there are a few different ways you could improve the performance of this code, but the key is to avoid changing the length of the alphabet string on each iteration of the inner for loop. Using a different data structure and/or a different approach for the inner for loop should help to make the code run more efficiently.