I am required to make a program that asks a user to input a list of numbers and then what function they'd like to apply, adn then print out the results. I have a few problems: It's saying I'm using variables before I assign them, it's saying invalid or unexpected types for my for loop, and I'm not sure the math functions will even 100% work.
I expected to be able to input a list of numbers and then do calculations based on the list and print out the results.
my code:
list = []
def median(list):
if len(list) == 0:
return 0
list.sort()
medianIndex = len(list) // 2
if len(list) %2 == 1:
return list[medianIndex]
else:
return (list[medianIndex] list[medianIndex - 1]) / 2
def mean(list):
if len(list) == 0:
return 0
list.sort()
total = 0
for number in list:
total = number
return total / len(list)
def mode(list):
numDict = {}
for digit in list:
number = numDict.get(digit, None)
if number == None:
numDict[digit] = 1
else:
numDict[digit] = number 1
maxVal = max(numDict.values())
modeList = []
for key in numDict:
if numDict[key] == maxVal:
modeList.append(key)
return modeList
else:
return 0
def main():
while True:
inputList = input("Enter a number: ")
if inputList == "":
break
list = inputList.split()
for i in range(len(list)):
list[i] = int(list[i])
list.append(inputList)
function = input("Enter what math function you'd like to use: ")
if function == "mean":
print("Here is the list and its mean: ", "\n", list, "\n", mean(list))
elif function == "median":
print("Here is the list and its median: ", "\n", list, "\n", median(list))
elif function == "mode":
print("Here is the list and its mode: ", "\n", list, "\n", mode(list))
else:
print("that is not a acceptable function, please retry.")
if __name__ == "__main__":
main()
errors I'm getting when running what's above:
Traceback (most recent call last):
File "C:\Users\Phillip\PycharmProjects\pythonProject-Snake_Game\stats.py", line 70, in <module>
main()
File "C:\Users\Phillip\PycharmProjects\pythonProject-Snake_Game\stats.py", line 61, in main
print("Here is the list and its mean: ", "\n", list, "\n", mean(list))
File "C:\Users\Phillip\PycharmProjects\pythonProject-Snake_Game\stats.py", line 25, in mean
list.sort()
TypeError: '<' not supported between instances of 'str' and 'int'
CodePudding user response：
this is how I would do it, made minor changes to only main function. everything else is same. compare it to yours.
def main(): list = [] while True: inputvar = input("Enter a number: ") print(type(inputvar)) if inputvar == "": break else: list.append(int(inputvar))
function = input("Enter what math function you'd like to use: ")
if function == "mean":
CodePudding user response：
I've made some tweaks to your program, added some type hints to the function parameters, made it a little more robust, and wrote some docstrings as well.
Here's my suggestion on how you might consider writing your app:
from typing import Any, List, Union
import re
Numeric = Union[int, float]
def to_number(num: Any) -> Any:
"""Convert numbers represented as strings to numeric values.
Parameters
----------
num : Any
Object that might contain a numeric value.
Returns
-------
Any
``num`` as either ``float``, ``int``, or ``unmodified``.
"""
try:
num = int(num)
except ValueError:
num = round(float(num), 4)
finally:
return num
def extract_numbers(text: str) -> List[Numeric]:
"""Extract all numbers from a string returning a list of numbers.
Parameters
----------
text : str
The string to extract numbers from.
Returns
-------
List[Numeric]
A list of numbers.
Examples
--------
>>> extract_numbers('1 2 3')
[1, 2, 3]
>>> extract_numbers('1.5,2.5,3.5')
[1.5, 2.5, 3.5]
"""
return [
to_number(num)
for num in re.findall(r"[- ]?\d*\.\d |\d ", text)
]
def median(_list: List[Numeric]) -> Numeric:
"""Return the median value from a list of numbers.
Parameters
----------
_list : List[Numeric]
A list of numbers.
Returns
-------
Numeric
The median value.
"""
if not _list:
return 0
_list.sort()
median_index = len(_list) // 2
if len(_list) % 2 == 1:
return _list[median_index]
return (_list[median_index] _list[median_index - 1]) / 2
def mean(_list: List[Numeric]) -> Numeric:
"""Compute the mean from a list of numbers.
Parameters
----------
_list : List[Numeric]
A list of numbers.
Returns
-------
Numeric
The mean value of the given ``_list``.
"""
return sum(_list) / len(_list) if _list else 0
def mode(_list: List[Numeric]) -> List[Numeric]:
"""Return the mode from a list of numbers.
Parameters
----------
_list : List[Numeric]
A list of numbers.
Returns
-------
List[Numeric]
A list with the mode(s) from ``_list``.
Examples
--------
>>> mode([1, 2, 3])
[1, 2, 3]
>>> mode([1, 1, 2, 3, 3])
[1, 3]
"""
num_dict = {
digit: _list.count(digit)
for digit in _list
}
max_val = max(num_dict.values())
return [key for key, value in num_dict.items() if value == max_val]
def main():
"""Main entry point for the program."""
print(f"{' Welcome to the List Calculator ':=^50}")
print("At any time, write \"q\" to exit the program")
while True:
input_list = input("Enter a number or list of numbers: ").lower()
if input_list in ["", "q", "quit"]:
print("Okay, bye!")
break
_list = extract_numbers(input_list)
if len(_list) == 0:
print("No values were entered, exiting program...")
break
function = input(
"Enter the name of the math operation you'd like to apply: "
).lower()
if function == "mean":
print("Here is the list and its mean:", _list, to_number(mean(_list)), sep="\n")
elif function == "median":
print(
"Here is the list and its median:", _list, to_number(median(_list)), sep="\n"
)
elif function == "mode":
print("Here is the list and its mode:", _list, mode(_list), sep="\n")
elif function in ["", "q", "quit"]:
print("Okay, bye!")
break
else:
print(
f"Unknown math operation \"{function}\". "
"Please choose one of the following operations: "
", ".join(["mode", "mean", "median"])
)
if __name__ == "__main__":
main()
Example usage:
