Server-Side Scripting/Strings and Files/Python (Flask)
app.py
edit# This program reads a user-selected text file of Fahrenheit
# temperatures and converts the temperatures to Celsius.
#
# File format:
# 32° F
# 98.6° F
# 212° F
#
# References:
# https://www.mathsisfun.com/temperature-conversion.html
# https://en.wikibooks.org/wiki/Python_Programming
# https://www.javatpoint.com/flask-file-uploading
import flask
app = flask.Flask(__name__)
FORM = """
<h1>Temperature Conversion</h1>
<p>Select a file of Fahrenheit temperatures for conversion:</p>
<form method="POST" enctype="multipart/form-data">
<input type="file" id="file" name="file">
<input type="submit">
</form>
"""
@app.route('/', methods=["GET"])
def root_get():
return FORM
@app.route('/', methods=["POST"])
def root_post():
file = flask.request.files["file"]
result = "<h1>Temperature Conversion</h1>"
result += f"<h2>{file.filename}</h2>"
result += process_file(file)
return result
def process_file(file):
if not file:
return "No file selected"
result = "<table><tr><th>Fahrenheit</th><th>Celsius</th></tr>"
text = file.read().decode()
lines = text.strip().split("\n")
for line in lines:
result += process_line(line)
result += "</table>"
return result
def process_line(line):
index = line.find("° F")
if index < 0:
return "Invalid file format"
try:
fahrenheit = float(line[0:index])
except:
return "Invalid temperature data"
celsius = (fahrenheit - 32) * 5 / 9
result = f"<tr><td>{fahrenheit}</td>"
result += f"<td>{celsius:.1f}</td></tr>"
return result
if __name__ == "__main__":
app.run(host='0.0.0.0', port=5000)
Try It
editCopy and paste the code above into the following free online development environment or use your own Python (Flask) compiler / interpreter / IDE.