我正在尝试编写一个python程序，用户输入多项式并计算导数。我目前的代码是：
print ("Derviatives: ")
k5 = raw.input("Enter 5th degree + coefficent: ")
k4 = raw.input("Enter 4th degree + coefficent: ")
k3 = raw.input("Enter 3rd degree + coefficent: ")
k2 = raw.input("Enter 2nd degree + coefficent: ")
k1 = raw.input("Enter 1st degree + coefficent: ")
k0 = raw.input("Enter constant: ")
int(k5)
int(k4)
int(k3)
int(k2)
int(k1)
int(k0)
print (k5, " ", k4, " ", k3, " ", k2, " ", k1, " ", k0)
1in = raw.input("Correct Y/N?")
if (1in != Y)
k5 = raw.input("Enter 5th degree + coefficent: ")
k4 = raw.input("Enter 4th degree + coefficent: ")
k3 = raw.input("Enter 3rd degree + coefficent: ")
k2 = raw.input("Enter 2nd degree + coefficent: ")
k1 = raw.input("Enter 1st degree + coefficent: ")
k0 = raw.input("Enter constant: ")
else
"""CODE GOES HERE"""
我只是一个初学的python程序员，所以我对一些基本的语法问题仍然有点模糊。我应该导入哪些库吗？
答案 0 :(得分：1)
好的，请使用raw_input代替raw.input。它内置，int，因此无需导入。转换为整数（int）时，需要分配结果，否则不会发生任何变化。您可以链接这些函数，并使用k5 = int(raw_input("prompt.. "))。此外，正如Evert所指出的，变量名不能以数字开头，因此必须更改1in。这段代码应该有效：
print("Derviatives: ")
k5 = raw_input("Enter 5th degree + coefficent: ")
k4 = raw_input("Enter 4th degree + coefficent: ")
k3 = raw_input("Enter 3rd degree + coefficent: ")
k2 = raw_input("Enter 2nd degree + coefficent: ")
k1 = raw_input("Enter 1st degree + coefficent: ")
k0 = raw_input("Enter constant: ")
k5 = int(k5)
k4 = int(k4)
k3 = int(k3)
k2 = int(k2)
k1 = int(k1)
k0 = int(k0)
print(k5, " ", k4, " ", k3, " ", k2, " ", k1, " ", k0)
in1 = raw_input("Correct Y/N?")
if in1 != "Y":
k5 = raw_input("Enter 5th degree + coefficent: ")
k4 = raw_input("Enter 4th degree + coefficent: ")
k3 = raw_input("Enter 3rd degree + coefficent: ")
k2 = raw_input("Enter 2nd degree + coefficent: ")
k1 = raw_input("Enter 1st degree + coefficent: ")
k0 = raw_input("Enter constant: ")
else:
"""CODE GOES HERE"""
另外，请检查您正在使用的python版本。如果是python 3，则需要将raw_input更改为input。如果您使用的是python 2，则不需要print语句中的括号。例如。 print("Derviatives: ") =＆gt; print "Derviatives: "。
答案 1 :(得分：0)
使用Sympy：
将这两行放在顶部：
from sympy import *
import numpy as np
这些部分是“”“代码在这里”“”
x = Symbol('x')
y = k5*x**5 + k4*x**4 + k3*x**3 + k2*x**2 + k1*x +constant
yprime = y.diff(x)
yprime
答案 2 :(得分：0)
我发现您的代码存在以下问题：
1in Y。我想你想要与字符串文字进行比较，所以请改为写"Y"。if运算符中不需要括号，但需要使用尾随冒号。同样适用于else。raw_input，而不是raw.input int(k5)会验证值（如果字符串不代表整数，则引发异常）它不会影响变量，因此k5仍然会包含一个字符串猜测显示一些代码不会有什么坏处，因为我没有在这里执行任务（实现算法），而只是显示语言功能。所以......我会这样做：
# There are no do...while-style loops in Python, so we'll do it this way
# loop forever, and break when confirmation prompt gets "y"
while True:
k = [] # That's an empty list.
# I'm assuming Python 2.x here. Add parentheses for Python 3.x.
print "Derivatives:"
# This range will work like a list [5, 4, 3, 2, 1].
for n in range(5, 1, -1):
k.append(int(raw_input("Enter {0}th degree + coefficient: ".format(n)))
## Or you could do it this way:
#for num in ["5th", "4th", "3rd", "2nd", "1st"]:
# k.append(int(raw_input("Enter {0} degree + coefficient: ".format(num)))
k.append(int(raw_input("Enter constant: ".format(n)))
# Here's a bit tricky part - a list comprehension.
# Read on those, they're useful.
# We need the comprehension, because our list is full of ints,
# and join experts a list of strings.
print " ".join(str(x) for x in k)
## If you didn't get the previous line - that's fine,
## it's fairly advanced subject. Just do like you're used to:
#print k[0], " ", k[1], " ", k[2], " ", k[3], " ", k[4], " ", k[5]
# Oh, and did you notice 5th coeff. is at k[0]?
# That's because we appended them to the list in reverse order.
# Let's reverse the list in-place, so the constant will be k[0] and so on.
k.reverse()
# You don't always need an intermediate variable for single-use values,
# like when asking for confirmation. Just put raw_input call directly
# in if statement condition - it would work just fine.
#
# And let's be case-insensitive here and accept both "Y" and "y"
if raw_input("Correct [Y/N]? ").lower() == "y":
break