Applied Programming/Conditions/Python3
conditions.py edit
"""This program converts a Fahrenheit temperature to Celsius.
Input:
Fahrenheit temperature
Output:
Fahrenheit temperature
Celsius temperature
Example:
Enter Fahrenheit temperature:
100
100.0° Fahrenheit is 37.8° Celsius
References:
* http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html
* https://wiki.python.org/moin/UsingAssertionsEffectively
* https://stackoverflow.com/questions/1278705/python-when-i-catch-an-exception-how-do-i-get-the-type-file-and-line-number
* http://www.mathsisfun.com/temperature-conversion.html
"""
import os
import sys
ABSOLUTE_ZERO = -459.67
def get_fahrenheit():
"""Gets Fahrenheit temperature.
Args:
None
Returns:
float: Fahrenheit temperature
Exits:
ValueError: If Fahrenheit temperature is not a valid float.
ValueError: If Fahrenheit temperature is below absolute zero.
"""
try:
print("Enter Fahrenheit temperature:")
fahrenheit = input()
fahrenheit = float(fahrenheit)
if fahrenheit < ABSOLUTE_ZERO:
print("Fahrenheit temperature cannot be below absolute zero.")
print(f"ValueError: {fahrenheit} is invalid."
os._exit(1)
return fahrenheit
except ValueError:
print("Fahrenheit temperature must be a floating point value.")
print(f"ValueError: {fahrenheit} is invalid.")
os._exit(2)
def fahrenheit_to_celsius(fahrenheit):
"""Converts Fahrenheit temperature to Celsius.
Args:
fahrenheit (float): Fahrenheit temperature to be converted
Returns:
float: Celsius temperature
Raises:
ValueError: If Fahrenheit temperature is not a valid float.
ValueError: If Fahrenheit temperature is below absolute zero.
"""
try:
fahrenheit = float(fahrenheit)
except ValueError:
raise ValueError(f"fahrenheit must be a float. Received '{fahrenheit}'")
except:
raise
if fahrenheit < ABSOLUTE_ZERO:
raise ValueError(f"fahrenheit must not be below absolute zero. Received '{fahrenheit}'")
TEMPERATURE_DIFFERENCE = 32
TEMPERATURE_RATIO = 5 / 9
celsius = (fahrenheit - TEMPERATURE_DIFFERENCE) * TEMPERATURE_RATIO
return celsius
def display_results(fahrenheit, celsius):
"""Displays Fahrenheit and Celsius temperatures.
Args:
fahrenheit (float): Fahrenheit temperature
celsuis (float): Celsius temperature
Returns:
None
Raises:
AssertionError: If Fahrenheit temperature is not a valid float.
AssertionError: If Celsius temperature is not a valid float.
"""
assert isinstance(fahrenheit, float) or isinstance(fahrenheit, int), \
"fahrenheit must be a float. Received {type(fahrenheit)}"
assert isinstance(celsius, float) or isinstance(celsius, int), \
"celsius must be a float. Received {type(celsius)}"
print(f"{fahrenheit}.1f° Fahrenheit is {celsius}.1f° Celsius")
def main():
"""Runs the main program logic."""
try:
fahrenheit = get_fahrenheit()
celsius = fahrenheit_to_celsius(fahrenheit)
display_results(fahrenheit, celsius)
except:
print("Unexpected error.")
print("Error:", sys.exc_info()[1])
print("File: ", sys.exc_info()[2].tb_frame.f_code.co_filename)
print("Line: ", sys.exc_info()[2].tb_lineno)
main()
Try It edit
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