Convert Strings To Mathematical Expressions In Python

Let’s learn how to convert strings to mathematical expressions in Python. To convert a string to a function in Python we need to use the eval method (eval()) as this will convert our string data type to a numerical data type that Python can interpret as a math function!

This timeline is meant to help you better understand how to convert strings to mathematical expressions in Python:
0:00 Introduction.
0:13 Convert Python function to Math function
0:58 Defining a math function as a Python function
1:37 Using the eval method in Python
2:24 Outro

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What is Python and why you should learn Python? Python programming, in particular Python 3, is a growing programming language that is loved by many programmers due to its simple syntax and ease of use. Python allows for relatively easy debugging of your codes and there are many beautiful Python IDE’s available for free to make coding more enjoyable. Python is also very popular among Data Scientists and many machine learning applications.

[spongebobseyelashes]

Excellent video, exactly what I needed for a bot I am working on. Thanks man!

[PoojaSharma-tbds]

Thank you so much!! You saved me today. I wasted so much of time trying to figure this out..

[jonathan_lol]

Thank you! I've been searching for this for hours!

[thehonestloaf]

This is so cool! Just made my numerical integration calculator usable with this. A LOT easier than I thought it would be, thanks!
But how do you use trig functions with this?

[nguyenanhquan]

The video is very helpful. Thanks a lot

[chickensalad]

heads up: using eval() to do something with user input isn't safe since code like os.system('rm -rf *') can be run from the user, which will delete every single file on the computer

[cozy-ventures]

Use eval at your own peril. It's extremely unsafe and if someone else can input the data it can cause havoc on your computer

[jotdown_C]

Lets say i have a list containing numerical elements. I would like to take the mathematical expression from the user and change the input list accordingly. Is there a way to do that.

[frosty]

great video, could you please help me, I'm trying to do math with a list of numbers, the list has had things appended to it with user input and I'm trying to then iterate over each appended number afterwards and print the percentage sum

[williamblair]

How can you do this without eval or make it safer?

[BILLPC]

is there a way to do this WITHOUT running the math calculations?

[danielliden]

I want to be able to do this:
3 calculation 4
The calculation shall be randomized between + - and *.
So Ive written
import random
calculation = random.choice(['*', '+', '-']) which gives me back a string.

But now I want to do have the calculation at random, how do I do that. I tried to do calculation = eval(random.choice(['*', '+', '-'])) but thats just gives me an error, any ideas?

[gabrielvkr]

Is there a method to evaluate a string inputed by user safely?

[weighted_tobelitaps]

Nice Video, but im thinking about, how to make sure, that the input is a mathematical expression. I have programmed a Discord Bot which should calculates expressions and draw the function. Currently it works. But not at all...my check, that its a matemathical expression is not perfect yet...and there are problems with other complicated functions...maybe you have a tip for me :D