Develop Reference

check if an attribute of a class is assigned to a instance

i'm making a little game for fun and i ran into an issue, how can i see if the email of a member is assigned to a instance?
file1:
if "test1#gmail.com" in file2:
print("ok"
else:
print("not ok")
file2:
player1 = Player("testName1", "test1#gmail.com", "testpwd1"
player2 = Player("testName2", "test2#gmail.com", "testpwd2"
player3 = Player("testName3", "test3#gmail.com", "testpwd3"
player4 = Player("testName4", "test4#gmail.com", "testpwd4"

overriding the __contains__ method will do the trick.
So:
def __contains__(self, key):
return key in self.email
Edit:
If for some reason you don't care which attribute contains the value, this will work:
def __contains__(self, key):
return key in list(self.__dict__.values())

If you put Players in a list then you could use a dictionary to index that list. This example lets you look up by name and email at the same time.
file2.py
class Player:
def __init__(self, name, email, pwd):
self.name = name.lower()
self.email = email.lower()
self.pwd = pwd
players = [
Player("testName1", "test1#gmail.com", "testpwd1"),
Player("testName2", "test2#gmail.com", "testpwd2"),
Player("testName3", "test3#gmail.com", "testpwd3"),
Player("testName4", "test4#gmail.com", "testpwd4")
]
# index to lookup up player by name or email
player_index = {player.name:player for player in players}
player_index.update({player.email:player for player in players})
file1.py
import file2
if file2.player_index.get("test1#mail.com".lower(), None) is not None:
print("ok")
else:
print("not ok")
It would be common to place that players list in some other data structure like a CSV file or even a pickled file. Assuming you want to update players dynamically, it becomes awkward to represent them as class instances in a .py file. But that's an enhancement for another time.

Problem adding and deleting objects from python class

Please can someone help me to fix the code, I want to create a school class and create an object. After that, I want to use the join function to add students ( if a student exists it will not add it and it will show a message, and if not exists it will add the student), same as the leave function (it will delete from the list only if exists). and finally, the show_all function will display all the values in the list. I think the structure of the code is wrong, so please can someone help me
class School:
def __init__(self):
print("A class has opened!")
def join(self, student):
self.student = student
if self.student not in my_school:
print(self.student +" is a new member of the school!")
else:
print("We already have "+ self.student +".")
def leave(self):
if self.student in my_school:
del self.student
else:
print("No such student")
def show_all(self):
print(my_school)
# create new object in class
my_school = School()
# add the student if not exists only
my_school.join('Sarah')
# delete if exists
my_school.leave("Noor")
# show all the list
my_school.show_all()

Your code has several errors:
When you call join (a bad method name, because it already exists) you reassign the student to single variable.
In leave you reference the instance witch is not possible because it doesn't jet exist.
Here is some code:
class School:
def __init__(self):
print("An instance of School was created!")
self.students = []
def join(self, student):
if student not in self.students:
self.students.append(student)
print(student + " is a new member of the school!")
else:
print("We already have "+ student +".")
def leave(self, student):
if student in self.students:
self.students.remove(student)
else:
print("No such student")
def show_all(self):
print(self.students)
# create new object in class
my_school = School()
# add the student if not in students
my_school.join("Sarah")
# delete the student if in the students list
my_school.leave("Noor")
# print the students
my_school.show_all()
This is by no means good code, but comes close to what you wanted to achieve.

Class object does not update empty list

I'm trying to solve this problem on my own. The problem asks to write a class for employee information, then ask user to input that information, and finally print the entered information.
I want to use two for loops, one for getting information and one for printing the information. Unfortunately, the printing for loop does not working.
class Employee:
def __init__(self, name, id_num, department, job):
self.__name = name
self.__id_num = id_num
self.__department = department
self.__job = job
# setters
def set_name(self,name):
self.__name = name
def set_id(self,id_num):
self.__id_num = id_num
def set_department(self,department):
self.__department = department
def set_job(self,job):
self.__job = job
# getters
def get_name(self):
return self.__name
def get_id(self):
return self.__id_num
def get_department(self):
return self.__department
def get_job(self):
return self.__job
def main():
employee_list = []
for i in range(2):
name = input('What is the name of the employee? ')
id_num = float(input('What is the ID number of the employee? '))
department = input('What is the department where the employee works? ')
job = input('What is the job title of the empoyee? ')
personnel = Employee(name,id_num,department,job)
employee_list.append(personnel)
return employee_list
for item in employee_list:
print(item.get_name())
print(item.get_id())
print(item.get_department())
print(item.get_job())
print()
main()

You need to remove the following line in your main() function:
return employee_list
It is causing your main to stop running without ever reaching the printing for loop.

I am looking to create instances of a class from user input

I Have this class:
class Bowler:
def __init__(self, name, score):
self.name = name
self.score = score
def nameScore(self):
return '{} {}'.format(self.name, self.score)
I need to get user input until a blank line is entered. Then use the data I got to create instances of a class. I was thinking something like:
def getData():
name, score = input("Please enter your credentails (Name score): ").split()
B1 = Bowler(name, score)
print(B1.nameScore())
But then I would somehow have to loop it until I get a blank user input. Also I would somehow have to create B2 B3 B4 etc in the loop.
Sorry I am still really new to programming, maybe I am looking at this from the wrong angle.

What you're looking for are Python Lists. With these you will be able to keep track of your newly created items while running the loop. To create a list we simply defined it like so:
our_bowlers = []
Now we need to alter our getData function to return either None or a new Bowler:
def getData():
# Get the input
our_input = input("Please enter your credentails (Name score): ").split()
# Check if it is empty
if our_input == '':
return None
# Otherwise, we split our data and create the Bowler
name, score = our_input.split()
return Bowler(name, score)
and then we can run a loop, check for a new Bowler and if we didn't get anything, we can print all the Bowlers we created:
# Get the first line and try create a Bowler
bowler = getData()
# We loop until we don't have a valid Bowler
while bowler is not None:
# Add the Bowler to our list and then try get the next one
our_bowlers.append(bowler)
bowler = getData()
# Print out all the collected Bowlers
for b in our_bowlers:
print(b.nameScore())

This is my code to do what you want:
class Bowler:
def __init__(self, name, score):
self.name = name
self.score = score
def nameScore(self):
return '{} {}'.format(self.name, self.score)
def getData():
try:
line = input("Please enter your credentails (Name score): ")
except SyntaxError as e:
return None
name, score = line.split()
score = int(score)
B = Bowler(name, score)
print(B.nameScore())
return B
if __name__ == '__main__':
bowlers = list()
while True:
B = getData()
if B == None:
break
bowlers.append(B)
for B in bowlers:
print(B.nameScore())
In addition, I recommend you to modify your input for it's inconvenient now

How can I use a returned value to open up another instance of a class in Python?

I am on exercise 43 doing some self-directed work in Learn Python The Hard Way. And I have designed the framework of a game spread out over two python files. The point of the exercise is that each "room" in the game has a different class. I have tried a number of things, but I cannot figure out how to use the returned value from their initial choice to advance the user to the proper "room", which is contained within a class. Any hints or help would be greatly appreciated.
Apologies for the poor code, I'm just starting out in python, but at my wit's end on this.
Here is the ex43_engine.py code which I run to start the game.
from ex43_map import *
import ex43_map
import inspect
#Not sure if this part is neccessary, generated list of all the classes (rooms) I imported from ex43_map.py, as I thought they might be needed to form a "map"
class_list = []
for name, obj in inspect.getmembers(ex43_map):
if inspect.isclass(obj):
class_list.append(name)
class Engine(object):
def __init__(self, room):
self.room = room
def play(self):
# starts the process, this might need to go inside the loop below
next = self.room
start.transportation_choice()
while True:
print "\n-------------"
# I have tried numerous things here to make it work...nothing has
start = StartRoom()
car = CarRoom()
bus = BusRoom()
train = TrainRoom()
airplane = AirplaneRoom()
terminal = TerminalRoom()
a_game = Engine("transportation_choice")
a_game.play()
And here is the ex43_map.py code
from sys import exit
from random import randint
class StartRoom(object):
def __init__(self):
pass
def transportation_choice(self):
print "\nIt's 6 pm and you have just found out that you need to get to Chicago by tomorrow morning for a meeting"
print "How will you choose to get there?\n"
print "Choices: car, bus, train, airplane"
choice = raw_input("> ")
if choice == "car":
return 'CarRoom'
elif choice == "bus":
return 'BusRoom'
elif choice == "train":
return 'TrainRoom'
elif choice == "airplane":
return 'AirplaneRoom'
else:
print "Sorry but '%s' wasn't a choice." % choice
return 'StartRoom'
class CarRoom(object):
def __init__(self):
print "Welcome to the CarRoom"
class BusRoom(object):
def __init__(self):
print "Welcome to the BusRoom"
class TrainRoom(object):
def __init__(self):
print "Welcome to the TrainRoom"
class AirplaneRoom(object):
def __init__(self):
print "Welcome to the AirplaneRoom"
class TerminalRoom(object):
def __init__(self):
self.quips = [
"Oh so sorry you died, you are pretty bad at this.",
"Too bad, you're dead buddy.",
"The end is here.",
"No more playing for you, you're dead."
]
def death(self):
print self.quips[randint(0, len(self.quips)-1)] # randomly selects one of the quips from 0 to # of items in the list and prints it
exit(1)

Instead of returning a string try returning an object, ie
if choice == "car":
return CarRoom()

It might be a good idea to make a Room class, and derive your other rooms from it.
The Room base class can then have a class variable which automatically keeps track of all instantiated rooms.
I haven't thoroughly tested the following, but hopefully it will give you some ideas:
# getters.py
try:
getStr = raw_input # Python 2.x
except NameError:
getStr = input # Python 3.x
getStr.type = str
def typeGetter(dataType):
def getter(msg):
while True:
try:
return dataType(getStr(msg))
except ValueError:
pass
getter.type = dataType
return getter
getInt = typeGetter(int)
getFloat = typeGetter(float)
getBool = typeGetter(bool)
def getOneOf(*args, **kwargs):
"""Get input until it matches an item in args, then return the item
#param *args: items to match against
#param getter: function, input-getter of desired type (defaults to getStr)
#param prompt: string, input prompt (defaults to '> ')
Type of items should match type of getter
"""
argSet = set(args)
getter = kwargs.get('getter', getStr)
prompt = kwargs.get('prompt', '> ')
print('[{0}]'.format(', '.join(args)))
while True:
res = getter(prompt)
if res in argset:
return res
.
# ex43_rooms.py
import textwrap
import random
import getters
class Room(object):
# list of instantiated rooms by name
ROOMS = {}
#classmethod
def getroom(cls, name):
"""Return room instance
If named room does not exist, throws KeyError
"""
return cls.ROOMS[name]
def __init__(self, name):
super(Room,self).__init__()
self.name = name
Room.ROOMS[name] = self
def run(self):
"""Enter the room - what happens?
Abstract base method (subclasses must override)
#retval Room instance to continue or None to quit
"""
raise NotImplementedError()
def __str__(self):
return self.name
def __repr__(self):
return '{0}({1})'.format(self.__class__.__name__, self.name)
class StartRoom(Room):
def __init__(self, name):
super(StartRoom,self).__init__(name)
def run(self):
print textwrap.dedent("""
It's 6 pm and you have just found out that you need to get to Chicago
by tomorrow morning for a meeting! How will you get there?
""")
inp = getters.getOneOf('car','bus','train','airplane')
return Room.getroom(inp)
class CarRoom(Room):
def __init__(self,name):
super(CarRoom,self).__init__(name)
class BusRoom(Room):
def __init__(self,name):
super(BusRoom,self).__init__(name)
class TrainRoom(Room):
def __init__(self,name):
super(TrainRoom,self).__init__(name)
class PlaneRoom(Room):
def __init__(self,name):
super(PlaneRoom,self).__init__(name)
class TerminalRoom(Room):
def __init__(self,name):
super(TerminalRoom,self).__init__(name)
def run(self):
print(random.choice((
"Oh so sorry you died, you are pretty bad at this.",
"Too bad, you're dead buddy.",
"The end is here.",
"No more playing for you, you're dead."
)))
return None
# create rooms (which registers them with Room)
StartRoom('start')
CarRoom('car')
BusRoom('bus')
TrainRoom('train')
PlaneRoom('airplane')
TerminalRoom('terminal')
.
# ex43.py
from ex43_rooms import Room
def main():
here = Room.getroom('start')
while here:
here = here.run()
if __name__=="__main__":
main()