How to remove 1 as a coefficient on my Python Code?-CodePudding

I have been looking at my code for awhile and need to return a polynomial given a dictionary. The polynomial output should not have any 1's as coefficients. Her e is my code:

class Polynomial:
  # Constructor
  def __init__(self, polyDict):
    self.polyDict = polyDict

  # String Method   
  def __str__(self):
    polyStr = ""
    firstTerm = True
    for exp, coeff in sorted(self.polyDict.items(), reverse=True):
      if coeff == 0:
        continue
      if firstTerm:
        if coeff > 0:
          polyStr  = str(coeff)
        else:
          polyStr  = str(coeff)
        if exp > 1:
          polyStr  = "x^"   str(exp)
        elif exp == 1:
          polyStr  = "x"
        firstTerm = False
      else:
        if coeff > 0:
          polyStr  = " "   str(coeff)
        else:
          polyStr  = str(coeff)
        if exp > 1:
          polyStr  = "x^"   str(exp)
        elif exp == 1:
          polyStr  = "x"
    return polyStr

print(Polynomial({6:-3, 5:6, 4:-1, 3:-2, 2:0, 1:1, 0:-3}))

I am unsure what else to try. I've staired at the code for a couple hours and dont know what to add.

CodePudding user response：

To fix the issue with the polynomial output having 1's as coefficients, you can modify the str method to check if the coefficient is 1 or -1 and not print it in the string representation of the polynomial. Here is an updated implementation of the str method that does this:

def __str__(self):
    polyStr = ""
    firstTerm = True
    for exp, coeff in sorted(self.polyDict.items(), reverse=True):
        if coeff == 0:
            continue
        if firstTerm:
            if coeff > 0:
                if coeff != 1:
                    polyStr  = str(coeff)
                if exp > 1:
                    polyStr  = "x^"   str(exp)
                elif exp == 1:
                    polyStr  = "x"
            else:
                if coeff != -1:
                    polyStr  = str(coeff)
                else:
                    polyStr  = "-"
                if exp > 1:
                    polyStr  = "x^"   str(exp)
                elif exp == 1:
                    polyStr  = "x"
            firstTerm = False
        else:
            if coeff > 0:
                if coeff != 1:
                    polyStr  = " "   str(coeff)
                else:
                    polyStr  = " "
                if exp > 1:
                    polyStr  = "x^"   str(exp)
                elif exp == 1:
                    polyStr  = "x"
            else:
                if coeff != -1:
                    polyStr  = str(coeff)
                else:
                    polyStr  = "-"

CodePudding user response：

I think this combines as much as can be combined.

class Polynomial:
    # Constructor
    def __init__(self, polyDict):
        self.polyDict = polyDict

    # String Method     
    def __str__(self):
        polyStr = ""
        firstTerm = True
        for exp, coeff in sorted(self.polyDict.items(), reverse=True):
            if coeff == 0:
                continue
            if coeff < -1 or (firstTerm and coeff > 1):
                polyStr  = str(coeff)
            elif coeff == -1:
                polyStr  = '-'
            elif coeff == 1:
                if not firstTerm:
                    polyStr  = ' '
            else:
                polyStr  = ' ' str(coeff)
            firstTerm = False

            if exp > 1:
                polyStr  = "x^" str(exp)
            elif exp == 1:
                polyStr  = "x"
        return polyStr

print(Polynomial({6:-3, 5:6, 4:-1, 3:-2, 2:0, 1:1, 0:-3}))