Getting user input

I am running this:

import csv
import sys
reader = csv.reader(open(sys.argv[0], "rb"))
for row in reader:
    print row

And I get this in response:

['import csv']
['import sys']
['reader = csv.reader(open(sys.argv[0]', ' "rb"))']
['for row in reader:']
['    print row']
>>>

For the sys.argv[0] I would like it to prompt me to enter a filename.

How do I get it to prompt me to enter a filename?

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

Use the raw_input() function to get input from users (2.x):

print "Enter a file name:",
filename = raw_input()

or just:

filename = raw_input('Enter a file name: ')

or if in Python 3.x:

filename = input('Enter a file name: ')

Method 2

In python 3.x, use input() instead of raw_input()

Method 3

sys.argv[0] is not the first argument but the filename of the python program you are currently executing. I think you want sys.argv[1]

Method 4

To supplement the above answers into something a little more re-usable, I’ve come up with this, which continues to prompt the user if the input is considered invalid.

try:
    input = raw_input
except NameError:
    pass

def prompt(message, errormessage, isvalid):
    """Prompt for input given a message and return that value after verifying the input.

    Keyword arguments:
    message -- the message to display when asking the user for the value
    errormessage -- the message to display when the value fails validation
    isvalid -- a function that returns True if the value given by the user is valid
    """
    res = None
    while res is None:
        res = input(str(message)+': ')
        if not isvalid(res):
            print str(errormessage)
            res = None
    return res

It can be used like this, with validation functions:

import re
import os.path

api_key = prompt(
        message = "Enter the API key to use for uploading", 
        errormessage= "A valid API key must be provided. This key can be found in your user profile",
        isvalid = lambda v : re.search(r"(([^-])+-){4}[^-]+", v))

filename = prompt(
        message = "Enter the path of the file to upload", 
        errormessage= "The file path you provided does not exist",
        isvalid = lambda v : os.path.isfile(v))

dataset_name = prompt(
        message = "Enter the name of the dataset you want to create", 
        errormessage= "The dataset must be named",
        isvalid = lambda v : len(v) > 0)

Method 5

Use the following simple way to interactively
get user data by a prompt as Arguments on what you want.

Version : Python 3.X

name = input('Enter Your Name: ')
print('Hello ', name)

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0