What is the while loop equivalent to this for loop?-CodePudding

I would like to convert both the for loops in my code into while loops. Here is the code.

class CountryCatalogue:
    def __init__(self, countryFile):  # constructor method that takes name of file
        self.countryCat = []  # The instance variable country cat needed
        file = open(countryFile, "r")  # open and read the file
        for strip in file:
            strip = strip.strip()
            data = strip.split('|')  # Remove '|' in each line
            clean_data = Country(data[0], data[2], data[3], data[1])  # Create an object to country
            self.countryCat.append(clean_data)  # Append the item to the list
        file.close()  # Close the file

    def setPopulationOfCountry(self, country, population):
        for pop in range(len(self.countryCat)):  # iterate through countryCat
            if self.countryCat[pop].getName() == country.getName():
                self.countryCat[pop].setPopulation(population)  # updating data if needed

I tried to change the second for loop this way:

def setPopulationOfCountry(self, country, population):
    pop = 0
    while pop < (len(self.countryCat)):
        if self.countryCat[pop].getName() == country.getName():
            self.countryCat[pop].setPopulation(population)  # updating data if needed
            pop = pop   1

But it didn't work and I wasn't sure about the first for Loop.

CodePudding user response：

your while loop:

def setPopulationOfCountry(self, country, population):
    pop = 0
    while pop < (len(self.countryCat)):
        if self.countryCat[pop].getName() == country.getName():
            self.countryCat[pop].setPopulation(population)  # updating data if needed
            pop = pop   1

you put the pop = pop 1 in the if statement, get it out:

def setPopulationOfCountry(self, country, population):
    pop = 0
    while pop < (len(self.countryCat)):
        if self.countryCat[pop].getName() == country.getName():
            self.countryCat[pop].setPopulation(population)  # updating data if needed
        pop = pop   1

CodePudding user response：

The easiest way that I found to change your file for loop to a while loop is to go through each line:

file = open(countryFile, "r")  # open and read the file
strip = file.readline()
while strip != "":
    strip = file.readline()