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Issue with implementing sympy into newtons method

I was trying to make a calculator for newtons method given a function, I've got everything down except that I keep running into an issue when I'm trying to do log of a different base or ln(x).
I'd appreciate the help!
import sympy as sp
x = sp.symbols('x')
# ask for expression and initial guess
expression = input('input function: ')
initial = float(input('input an initial guess: '))
iterate = int(input('input how many times you want it to iterate: '))
# find derivative of function
f_prime = sp.diff(expression, x)
f = sp.lambdify(x, expression, 'numpy')
df = sp.lambdify(x, f_prime, 'numpy')
# newtons method rounded to 8 decimal places
for i in (1, iterate):
i = initial - (f(initial)/df(initial))
initial = round(i, 8)
print(f'The root is {initial} after {iterate} iterations')
Everytime I put in log of a different base it would give me
TypeError: return arrays must be of ArrayType or a name error
for ln(x) it would give me
AttributeError: 'Symbol' object has no attribute 'ln'. Did you mean: 'n'?

The output of your expression = input('input function: ') is of type string. Before creating f = sp.lambdify(...) you need to convert that expression into a symbolic expression. sympify is the command you need to use:
expression = sp.sympify(input('input function: '))

How to get string and int as input in one line in Python3?

I have seen the below link for my answer but still didn't get an expected answer.
If I provide Name and Number in one line, Python should take the first value as a string and second as an integer.

a, b = [int(x) if x.isnumeric() else x for x in input().split()]
It will convert to int any part of input if possible.

s, num = input("Give str and int :\n").split()
num = int(num)
print(s, type(s))
print(num, type(num))
Output :
Give str and int :
hello 23
hello <class 'str'>
23 <class 'int'>

If you're certain to have a string and a number you can use list comprehension to get the values of both.
x = "Hello 345"
str_value = "".join([s for s in x if s.isalpha()]) # list of alpha characters and join into one string
num_value = int("".join([n for n in x if n.isdigit()])) # list of numbers converted into an int
print(str_value)
>> Hello
print(num_value)
>> 345

You can get the string and int by using regular expressions as follows:
import re
input_text = "string489234"
re_match = re.match("([^0-9]*) ?([0-9]*)", input_text)
if re_match:
input_str = re_match.group(1)
input_int = re_match.group(2)
see: https://docs.python.org/3/library/re.html

Read numbers from string into float

I need to convert some strings to float. Most of them are only numbers but some of them have letters too. The regular float() function throws an error.
a='56.78'
b='56.78 ab'
float(a) >> 56.78
float(b) >> ValueError: invalid literal for float()
One solution is to check for the presence of other characters than numbers, but I was wondering if there is some built-in or other short function which gives:
magicfloat(a) >> 56.78
magicfloat(b) >> 56.78

You can try stripping letters from your input:
from string import ascii_lowercase
b='56.78 ab'
float(b.strip(ascii_lowercase))

use a regex
import re
def magicfloat(input):
numbers = re.findall(r"[-+]?[0-9]*\.?[0-9]+", input)
# TODO: Decide what to do if you got more then one number in your string
if numbers:
return float(numbers[0])
return None
a=magicfloat('56.78')
b=magicfloat('56.78 ab')
print a
print b
output:
56.78
56.78

Short answer: No.
There is no built-in function that can accomplish this.
Longish answer: Yes:
One thing you can do is go through each character in the string to check if it is a digit or a period and work with it from there:
def magicfloat(var):
temp = list(var)
temp = [char for char in temp if char.isdigit() or char == '.']
var = "".join(temp)
return var
As such:
>>> magicfloat('56.78 ab')
'56.78'
>>> magicfloat('56.78')
'56.78'
>>> magicfloat('56.78ashdusaid')
'56.78'
>>>

Pass Variables within Python Class

I have the following class. But when trying to pass the variable x to the re.match it doesnt appear to correctly work as whatever input I put in it returns "invalid"
class validate:
def __init__(self, input_value):
self.input_value = input_value
def macaddress(self, oui):
self.oui = oui
#oui = 0, input deemed valid if it matches {OUI:DEVICE ID}.
#oui = 1, input deemed valid if it matches {OUI}.
if self.oui == 0:
x = 5
elif self.oui == 1:
x = 2
if re.match("[0-9a-fA-F]{2}([.-: ][0-9a-fA-F]{2}){x}$", self.input_value):
return "valid"
else:
return "invalid"
Should I be passing var x in some other manner ?
Thanks,

Insert x into the string this way (using string formatting):
Python <2.7:
if re.match("[0-9a-fA-F]{2}([.-: ][0-9a-fA-F]{2}){%d}$" % x, self.input_value):
However if you use the python 3 way of formatting, your regex interferes.
It can be cleaner (but slower) to use concatenation.
Without concatenation:
if re.match("[0-9a-fA-F]\{2\}([.-: ][0-9a-fA-F]\{2\}){0}$".format(x), self.input_value):
With concatenation:
if re.match("[0-9a-fA-F]{2}([.-: ][0-9a-fA-F]{2})" + x + "$", self.input_value):
Note: this fails if implicit type conversion is not possible.
If you just put {x} in the middle of your string, Python doesn't actually do anything with it unless string formatting is applied.

String reversal in Python

I have taken an integer input and tried to reverse it in Python but in vain! I changed it into a string but still I am not able to. Is there any way to reverse it ? Is there any built-in function?
I am not able to convert the integer into a list so not able to apply the reverse function.

You can use the slicing operator to reverse a string:
s = "hello, world"
s = s[::-1]
print s # prints "dlrow ,olleh"
To convert an integer to a string, reverse it, and convert it back to an integer, you can do:
x = 314159
x = int(str(x)[::-1])
print x # prints 951413

Code:
>>> n = 1234
>>> print str(n)[::-1]
4321

>>> int(''.join(reversed(str(12345))))
54321