遍历列表并将值分配给Python中的变量

Question

So i'm currently working on code, which solves simple differentials. For now my code looks something like that:

deff diff():
coeffs = []
#checking a rank of a function
lvl = int(raw_input("Tell me a rank of your function: "))
if lvl == 0:
    print "\nIf the rank is 0, a differential of a function will always be 0"
#Asking user to write coefficients (like 4x^2 - he writes 4)
for i in range(0, lvl):
    coeff = int(raw_input("Tell me a coefficient: "))
    coeffs.append(coeff)
#Printing all coefficients
print "\nSo your coefficients are: "
for item in coeffs:
    print item  

And so what I want to do next? I have every coefficient in my coeffs[] list. So now I want to take every single one from there and assign it to a different variable, just to make use of it. And how can I do it? I suppose I will have to use loop, but I tried to do so for hours - nothing helped me. Sooo, how can I do this? It would be like : a=coeff[0], b = coeff[1], ..., x = coeff[lvl] .

Answer 1

If you REALLY want to assign a list to variables you could do so by accessing the globals() dict. For example:

for j in len(coeffs):
     globals()["elm{0}".format(j)] = coeffs[j]

Then you'll have your coefficients in the global variables elm0 , elm1 and so on.

Please note that this is most probably not what you really want (but only what you asked for).

Answer 2

Just access the coefficients directly from the list via their indices.

If you are wanting to use the values in a different context that entails making changes to the values but you want to keep the original list unchanged then copy the list to a new list,

import copy

mutableCoeffs = copy.copy(coeffs)

Answer 3

You do not need new variables.

You already have all you need to compute the coefficients for the derivative function.

print "Coefficients for the derivative:"
l = len(coeffs) -1
for item in coeffs[:-1]:
    print l * item
    l -=1

Or if you want to put them in a new list :

deriv_coeffs = []
l = len(coeffs) -1
for item in coeffs[:-1]:
    deriv_coeffs.append(l * item)
    l -=1

Answer 4

I guess from there you want to differenciate no? So you just assign the cofficient times it rank to the index-1?

deff diff():

    coeffs = []
    #checking a rank of a function
    lvl = int(raw_input("Tell me a rank of your function: "))
    if lvl == 0:
        print "\nIf the rank is 0, a differential of a function will always be 0"
    #Asking user to write coefficients (like 4x^2 - he writes 4)
    for i in range(0, lvl):
        coeff = int(raw_input("Tell me a coefficient: "))
        coeffs.append(coeff)
    #Printing all coefficients
    print "\nSo your coefficients are: "
    for item in coeffs:
        print item  
    answer_coeff = [0]*(lvl-1)
    for i in range(0,lvl-1):
        answer_coeff[i] = coeff[i+1]*(i+1)
    print "The derivative is:"
    string_answer = "%d" % answer_coeff[0]
    for i in range(1,lvl-1):
        string_answer = string_answer + (" + %d * X^%d" % (answer_coeff[i], i))
    print string_answer