Comma-Separated Values , Make it Beautiful! , Filter the Output

Comma-Separated Values
CSV files are a way of storing a spreadsheet as a text file. Every value in the file is separated by a comma.
Hence the name...
Look, it's basically a spreadsheet.
Opening A CSV File
Fortunately, CSV files are so common that Python already has built-in libraries for working with them.
👉 The csv file 'January.csv' has been added for you. Let's see what happens:
import csv # Imports the csv library
with open("January.csv") as file: # Opens the csv file
reader = csv.reader(file) # reads the contents of the csv file into the 'reader' variable
line = 0
for row in reader: # loop to output each row in the 'reader' variable one at a time.
print (row)

This works, but the output isn't very pretty. And we like pretty.

Make it Beautiful!

👉 Let's use join. It allows us combine lists in a more interesting way.

import csv
with open("January.csv") as file:
reader = csv.reader(file)
line = 0
for row in reader:
print (", ".join(row)) # adds a comma and space and then joins data, you could try joining with tabs too with `\t`

Filter the Output

👉 The trick is to treat the CSV like a dictionary, using the csv.DictReader() function. In the code below, I've filtered it so that it only shows the net total from each day.

import csv # Imports the csv library
with open("January.csv") as file:
reader = csv.DictReader(file) # Treats the file as a dictionary
line = 0
for row in reader:
print (row["Net Total"])

Now let's see if we can add the net totals from each day to create a total. Note that I've cast the data as a float because our library will treat it as text.

import csv # Imports the csv library
with open("January.csv") as file:
reader = csv.DictReader(file) # Treats the file as a dictionary
total = 0
for row in reader:
print (row["Net Total"])
total += float(row["Net Total"]) # Keeps a running total
print(f"Total: {total}") #Outputs

Comments

CONTINUE COMMAND AND EXIT LINE

The Continue Command The continue command stops executing code in the loop and starts at the top of the loop again. Essentially, we want to kick the user back to the original question. EXAMPLE : while True: print("You are in a corridor, do you go left or right?") direction = input("> ") if direction == "left": print("You have fallen to your death") break elif direction == "right": continue else: print("Ahh! You're a genius, you've won") NOTE : The else statement refers to any input besides left or right (up or esc). Since the user is a winner, we do not want to use break or it would say they have failed. EXIT COMMAND LINE The previous code continues to loop even after the user has won. Let's fix that with the exit() command EXAMPLE: print("Let's play chutes and ladders. Pick ladder or chute.") while...

FOR LOOP , RANGE

FOR LOOP A while loop is perfect to use when we don't know how many times we want the loop to repeat. If we have an idea of how many times we want the loop to repeat, we can use a for loop to loop code in exactly the same way the while loop did. EXAMPLE : for counter in range(10): print(counter) RANGE The range function creates a list of numbers in the range you create. If you only give it one number, it will start at 0 and move to a state where the final number is one less than the number in the brackets. In this case, the final number would be 9 . EXAMPLE : total = 0 for number in range(100) : total += number print(total)

Automate! Automate!

Making this customizable 👉So how about making our search user customizable? In the code below, I have: Asked the user to input an artist (line 14) Tidied up their input (line 15) formatted the search URL as an fString that includes the artist (line 19) Here's tAutomate! Automate! We are so close. I can taste it, folks! Massive kudos on getting this far! Today's lesson, however, will work best if you have one of Replit's paid for features (hacker plan or cycles). Free plan Repls 'fall asleep' after a while. Automation kinda relies on the Repl being always on. If you have hacker plan or you've bought some cycles, then you can enable always on in the drop down menu that appears when you click your Repl name (top left).he code: This is important because when our repl is always running, it can keep track of time and schedule events. 👉 I've set up a simple schedule that prints out a clock emoji every couple of seconds. It works like this: Import schedule librar...

PYTHON SYNTAX

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