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Maximum Collatz length in Python, but output is not correct [closed]

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This is my first time posting to Stackoverflow.
I'm trying to solve this problem here: https://codingbat.com/prob/p270692?parent=/home/konstans#stuy.edu/all
When looking at all hailstone sequences from 1 to z, maxHail(z) will return the starting number that creates the longest sequence. In other words, maxHail(n) looks at hailLen(1), hailLen(2) ... hailLen(n) and returns the number from 1-n that had the largest hailstone sequence. You should look at the hailLen() problem before working on this. You should use your solution from the hailLen() problem. ( http://codingbat.com/author/p264289 ) since hailLen(3) is larger than the hailLen of 4 or 5, maxHail of 3,4,5 all return 3. Since 6 has a longer sequence, maxHail(6) gives us 6. remember: Use the hailLen function you already wrote!
Here's my code and the output:
However, I'm not sure where this goes wrong - I checked line-by-line and couldn't see anything wrong. Could anyone help me fix this? Thank you!

I see what is wrong - hailLen returns lenght of sequence and the question is about index for which the sequence is the longest. Just store it in variable
if (res := hailLen(i)) > counter: # it's python 3.8 syntax
counter = res
index = i
return index

How can I sort the a list of strings which contain date as substring [closed]

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Below is my list,
['pending/', 'pending/2021-08-01/', 'pending/2021-06-01/', 'pending/2021-06-18/']
And I need to sort the list and filter it to a below format. Please suggest a quicker way to achieve it
['pending/2021-06-01/', 'pending/2021-06-18/', 'pending/2021-08-01/']

When your format is fixed and always starts with "pending" you can use the normal sorted function and count the / in a list comprehension.
>>> values = ['pending/', 'pending/2021-08-01/', 'pending/2021-06-01/', 'pending/2021-06-18/']
>>> sorted(x for x in values if x.count('/') == 2)
['pending/2021-06-01/', 'pending/2021-06-18/', 'pending/2021-08-01/']

Sort list that includes float numbers and words with number [closed]

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I'm trying to sort a list with the following values
My list
list_to_sort = ['1.1.0','1.2.3','1.3.10','1.3.9','x23','hi']
My expected output
['1.1.0','1.2.3','1.3.9','1.3.10','hi','x23']
What i have tried:
list_to_sort .sort()
I have never done something like this so I would love to know how I could solve it. Thanks!

This was, needless to say, an interesting one to solve
list_to_sort = ['1.1.0', '1.2.0','4.3.0' ,'1.3.10','1.3.9','1.31.0','x23','hi']
def weirdFloats(x):
try:
#trips an error when given something like "hi"
return [int(i) for i in x.split(".")]
except:
return [float("Inf"), x]
print(sorted(list_to_sort, key= weirdFloats, reverse= False))
['1.1.0', '1.2.0', '1.3.9', '1.3.10', '1.31.0', '4.3.0', 'hi', 'x23']
Note that im not sure if this properly accounts for things that cant be interpreted as what you call "floats" (they look more like version #'s to me) such as what seem to be the outliers here hi and x23

splitting terms in a polynomial expression without external libraries like sympy [closed]

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Say i inputted "1+2x+3x^2" or "1-2x+3x^2"
How do i make a function that splits and makes a list of each term like [1, 2x, 3x^2] or [1, -2x, 3x^2].
I have been stumped at this for a while, for now the function im using currently, seperates only at the "+" so to get a list like [1, -2x, 3x^2] i have to input
"1+-2x+3x^2"
Note: I won't be using complex polynomials but simple looking ones that doesn't include parenthesis or fractions.

import re
s = '1+2x^2-3x^-3'
s = re.sub('\^-', 'neg', s) # trick to deal the negative powers
print(s)
s=s.replace('-','+-')
s=s.replace('neg','-')
sub = s.split('+')
print(sub)
This will split your negative power variables correctly.

using split for appending to multiple lists [closed]

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Is it possible to combine the two statements inside 'for' loop.
num_pro=raw_input("ENTER THE NUMBER OF PRODUCTIONS: ")
right=[];left=[];
for i in range(int(num_pro)):
l,r=raw_input("ENTER PRODUCTION"+str(i+1)+" : ").split('->')
right.append(r);left.append(l)
sample input: E->abc

Append tuples to one list, then split out the lists using zip():
entries = []
for i in range(int(num_pro)):
entries.append(raw_input("ENTER PRODUCTION"+str(i+1)+" : ").split('->'))
left, right = zip(*entries)
zip(*iterable) transposes the nested list; columns become rows. Because you have two 'columns' (pairs of values), you end up with two rows instead.

Not without making it more complex. Each method needs to be called individually, and the only way to do that is either explicitly, as you have done, or in a loop.
If you are willing to store the whole production (which isn't necessarily a bad idea, since it keeps both sides synchronized) then just append the split result instead.
productions = []
for ...
productions.append(....split('->'))