Building a function to read CSV

I am new to Python and building a function to read CSV. I am trying to use the pandas.read_csv() inside my function,and while the code gets compiled-i dont see the dataset (I know its an overkill, but am trying to learn it using a trial and error method).

>>> def CSV(filename):
        dataset=pd.read_csv(filename)

I expect that when i run CSV('abc.csv'), it should create a df in my variable explorer. Unfortunately, the function gets compiled, but nothing is there

def CSV(filename):
    dataset=pd.read_csv(filename)

CSV('banking.csv')

Answer

The following example, taken from Read the Docs: Variables and Scope, illustrates the issue that you’re experiencing — dataset was created in your CSV function, but no longer exists outside of the scope of that function:

# This is a global variable
a = 0

if a == 0:
    # This is still a global variable
    b = 1

def my_function(c):
    # this is a local variable
    d = 3
    print(c)
    print(d)

# Now we call the function, passing the value 7 as the first and only parameter
my_function(7)

# a and b still exist
print(a)
print(b)

# c and d don't exist anymore -- these statements will give us name errors!
print(c)
print(d)

In this example, variable d is similar to your dataset variable — it’s trashed as soon as execution of the function is complete.

Instead:

def CSV(filename):
    return pd.open_csv(filename)

df = CSV('banking.csv')

will create a DataFrame variable df that you can view in variable explorer.