CODEWITHSUNDEEP
pythonloops
user1810514
user1810514

Reputation: 47

How to create a number of variables from a number entered by user

I am creating a script that asks the user how many data sets they would want to compare.

The user enters a number and I was wondering if there is a way, using loops, to creating a number of variables for the number the user entered. 

input_SetNum = input("How many data sets are you comparing: ")
print ("You entered " + input_SetNum) 

data_sets = {}
for i in range(1, input_SetNum+1):
data_sets[i] = input("Please enter the file path a data set: ")

Upvotes: 1

Views: 86

Answers (4)

Deacon
Deacon

Reputation: 3803

You're definitely on the right path. Your code isn't that different than what I would generate for this same task. Most of my changes are a matter of preference, mainly that I'd use a list instead of a dictionary, since there doesn't appear to be any overwhelming reason to use a dictionary in this case; you appear to mainly be using it in the same way you'd use an array in another language, or as a list that you don't need to explicitly .append() or .extend() new items to.

# Python 3.  For Python 2, change `input` to `raw_input` and modify the
# `print` statement.
while True:  # Validate that we're getting a valid number.
    num_sets = input('How many data sets are you comparing?  ')

    try:
        num_sets = int(num_sets)

    except ValueError:
        print('Please enter a number!  ', end='')

    else:
        break

data_sets = []

# Get the correct number of sets.  These will be stored in the list,
# starting with `data_sets[0]`.
for _ in range(num_sets):
    path = input('Please enter the file path a data set:  ')
    data_sets.append(path)

If you entered 3 for the number of sets, this would set data_sets equal to

['data_set_0', 'data_set_2', 'data_set_3']

for the appropriate input.

Upvotes: 0

michaelpri
michaelpri

Reputation: 3651

You could use a dictionary. 

data_sets = {}
for i in range(1, input_SetNum+1):
    data_sets[i] = # data set value here

Edit:

If you are using Python 3, then you full code should be:

input_SetNum = input("How many data sets are you comparing: ")
print ("You entered " + input_SetNum) 

data_sets = {}
for i in range(1, int(input_SetNum)+1):
    data_sets[i] = input("Please enter the file path a data set: ")

print(data_sets)

Printing data_sets will produce this result when 3 is inputted:

{1: '/path/file1', 2: '/path/file2', 3: '/path/file3'}

If you are using Python 2.7, then you should replace all of the input()s with raw_inputs.

Edit 2:

To open CSV files based on their paths, you can use code like this under what you've already done.

for key in data_sets:
    with open(data_sets[key]) as current_file:
        # do stuff here

It may also be possible to instead use open() on the input() you used before for the file path. 

data_sets[i] = open(input("Please enter the file path a data set: "))

I am not 100% sure if this will work, as I am not very familiar with CSV files, but it can't hurt and if it does work, it would be easier to compare the data sets.

Upvotes: 2

Ed Smith
Ed Smith

Reputation: 13216

You can define variables in the workspace using

for i in input_SetNum:
    vars()["var%s=value" % (i)] = value

You will probably want to put this inside a class in the long term, where the variables for the class are defined by,

class SomeObj:
    def __init__(self, input_SetNum, values):
        for i in input_SetNum:
            vars(self)["var%s=value" % (i)] = values[i]

Upvotes: 0

zmbq
zmbq

Reputation: 39023

Just use a list - with an element for each number.

Upvotes: 1

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