File I/O

The code will first generate random data and write to a file data.txt. The next block of code will read data from data.txt , parse this data and print this data on the console.

with keyword used in the below code ensures that the opened file is closed at the end of read or write operations.

Feather Sense may not allow writing of file at runtime. To resolve this, remove file-writing part of the code and manually create data.txt file in CIRCTUITPY drive.

file = open("data.txt", "r")  # Open the file for reading
for line in file:  # Loop through each line in the file
    values = line.strip().split(",")  # Split the line into a list of values
    tup = tuple(values)  # Convert the list of values into a tuple
    print(tup)  # Print the tuple
file.close()  # Close the file

  1. file = open("data.txt", "r"): This line opens the file called data.txt in read-only mode ("r") and assigns it to the variable file. The file is now ready to be read from.

  2. for line in file:: This line starts a for loop that loops through each line in the file. The loop iterates over each line in the file, and assigns each line to the variable line.

  3. values = line.strip().split(","): This line strips any leading or trailing whitespace from the line using the strip() method, and then splits the line into a list of values using the split(",") method. The split() method takes a delimiter as an argument and splits the string at each occurrence of the delimiter. In this case, the delimiter is a comma (","), so the line is split into a list of values wherever there's a comma.

  4. tup = tuple(values): This line creates a tuple called tup from the list of values. The tuple() function takes an iterable (in this case, a list) as an argument and returns a tuple with the same elements. In Python, a tuple is a collection of values, just like an array. However, unlike arrays, tuples are immutable, which means that once a tuple is created, it cannot be modified. We can access the values in the tuple using indexing, just like with an array: print(my_tuple[0]) # prints 1

  5. print(tup): This line prints the tuple to the console.

  6. file.close(): This line closes the file after we've finished reading from it. This is important to release any system resources used by the file and prevent any potential issues with the file in the future.

Overall, this code opens a file, reads each line from the file, splits each line into a list of values using a comma as a delimiter, converts the list of values into a tuple, and then prints each tuple to the console. It's a simple way to read a CSV file in Python and work with the data in a structured format.

Sample data.txt

1,2,3,4,5,6
7,8,9,10,11,12
13,14,15,16,17,18
19,20,21,22,23,24
25,26,27,28,29,30

Another version of the file reading code

import random
import time
with open("data.txt", "w") as fhandle:
    for i in range(1024):
        x1 = random.randint(1,255)
        #x2 = random.randint(1,255)
        #fhandle.write(str(x1) + "," + str(x2) + "\n")
        fhandle.write(str(x1) + "\n")

data = []
with open("data.txt", "r") as fhandle:
    for line in fhandle:
        line=line.rstrip('\n')
        line=line.rstrip('\r')
        data.append(line.split(','))

while True:
    for row in data:
        print(row)
        time.sleep(0.5)

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