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BHUVANESH M
BHUVANESH M

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Stop Overcomplicating Input Parsing

Tired of writing multiple lines to convert string input into a list, tuple, or dictionary in Python?

Ever wondered if there's a shortcut to parse user inputs as-is?

Letโ€™s unlock the underrated but powerful eval() function! โšก


๐Ÿง  The Problem

You're building a CLI tool or a quick script and want to allow user input like:

[1, 2, 3]  # List  
(4, 5, 6)  # Tuple  
{"name": "bhuvanesh"}  # Dictionary
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Using input() gives you strings โ€” not the actual data types.

So instead of this:

data = input("Enter list: ")
# Now you need to manually parse or use json.loads()
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Wouldnโ€™t it be cool to directly get a list/tuple/dict?


โœ… The Classic eval() Solution

user_input = input("Enter any Python literal: ")
parsed = eval(user_input)
print(type(parsed), parsed)
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๐ŸŽฏ Just like that, the input '[1, 2, 3]' becomes a list object.


โš ๏ธ Warning: Use with Caution

eval() executes any code. So it's unsafe if the input comes from an untrusted source.

# Potentially dangerous
eval("__import__('os').system('rm -rf /')")
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๐Ÿ‘ฎโ€โ™‚๏ธ Use it only in controlled environments, like local scripts, learning, or quick utilities.


๐Ÿ” Safer Alternative: ast.literal_eval

If you're dealing only with basic Python literals, use:

import ast

safe_data = ast.literal_eval(input("Enter literal: "))
print(type(safe_data), safe_data)
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โœ… Safer

โœ… No arbitrary code execution

โœ… Handles strings, numbers, lists, dicts, etc.


๐Ÿงช Try These Examples

Input: [10, 20, 30]      โžœ Output: <class 'list'> [10, 20, 30]
Input: (1, 2)            โžœ Output: <class 'tuple'> (1, 2)
Input: {"id": 123}       โžœ Output: <class 'dict'> {'id': 123}
Input: 'hello world'     โžœ Output: <class 'str'> hello world
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๐Ÿ Quick Summary

โœ… eval() turns string input into real Python objects

โš ๏ธ Risky with unknown input โ€” use only when safe

โœ… Use ast.literal_eval() for secure parsing

๐Ÿš€ Handy for quick data entry, debugging, or interactive tools


๐Ÿ’ฌ Do you use eval() in your projects? Prefer safer methods?

Let's discuss in the comments!


๐Ÿ“– More Python๐Ÿ tips by @bhuvaneshm_dev

Keep exploring these small Python features that make a big impact in productivity!


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