Udemy - 100 Days of Code: The Complete Python Pro Bootcamp
Day 30 - Errors, Exceptions and JSON Data
目录
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- [228. Catch Exceptions](#228. Catch Exceptions)
- [229. Raise Exceptions](#229. Raise Exceptions)
- [230. Improve the NATO Alphabet Project](#230. Improve the NATO Alphabet Project)
- [231. Read and Write JSON Data](#231. Read and Write JSON Data)
- [232. Improve the Password Manager Project](#232. Improve the Password Manager Project)
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228. Catch Exceptions
try：Something that might cause an exception 可能引发异常的代码
except：Do this if there was an exception 发生异常时执行的代码
else：Do this if there were no exceptions 没有异常时执行的代码
finally：Do this no matter what happens 不管有没有异常都会执行的代码
python
try:
file = open("file.txt", "r", encoding="utf-8")
content = file.read()
except FileNotFoundError:
print("File was not found, creating a new file.")
file = open("file.txt", "w", encoding="gbk")
file.write("你好")
except UnicodeDecodeError as e:
print(f"Encoding error: {e}")
else:
print(f"File content: {content}")
finally:
print("File was closed.")
file.close() 229. Raise Exceptions
python
height = float(input("Height (m): "))
weight = float(input("Weight (kg): "))
if height > 3:
raise ValueError("Human Height should not be over 3 meters.")
bmi = weight / height ** 2
print(bmi)230. Improve the NATO Alphabet Project
python
import pandas
df = pandas.read_csv("nato_phonetic_alphabet.csv")
phonetic_dict = {row.letter: row.code for index, row in df.iterrows()}
print(phonetic_dict)
def generate_alphabet():
word = input("Enter a word: ").upper()
try:
output_list = [phonetic_dict[letter] for letter in word]
except KeyError:
print("Sorry, only letters in the alphabet please.")
generate_alphabet()
else:
print(output_list)
generate_alphabet()231. Read and Write JSON Data
python
import json # JavaScript Object Notation JavaScript对象表示法
# Read JSON Data (JSON String -> Python Object)
json_str = '{"name":"John", "age":30, "city":"New York"}'
data = json.loads(json_str)
print(data)
# Write JSON Data (Python Object -> JSON String)
data = {
"name": "John",
"age": 30,
"city": "New York"
}
json_str = json.dumps(data, indent=4)
print(json_str)
# Read JSON Data (JSON File -> Python Object)
with open("data.json") as file:
data = json.load(file)
print(data)
# Write JSON Data (Python Object -> JSON File)
data = {
"name": "John",
"age": 30,
"city": "New York"
}
with open("data.json", mode="w") as file:
json.dump(data, file, indent=4) 232. Improve the Password Manager Project
python
from tkinter import *
from tkinter import messagebox
from random import choice, randint, shuffle
import pyperclip
import json
def generate_password():
letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
numbers = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
symbols = ['!', '#', '$', '%', '&', '(', ')', '*', '+']
password_letters = [choice(letters) for _ in range(randint(8, 10))]
password_symbols = [choice(symbols) for _ in range(randint(2, 4))]
password_numbers = [choice(numbers) for _ in range(randint(2, 4))]
password_list = password_letters + password_symbols + password_numbers
shuffle(password_list)
password = "".join(password_list)
password_entry.delete(0, END)
password_entry.insert(0, password)
pyperclip.copy(password)
def save():
website = website_entry.get()
email = email_entry.get()
password = password_entry.get()
new_data = {
website: {
"email": email,
"password": password,
}
}
if len(website) == 0 or len(email) == 0 or len(password) == 0:
messagebox.showinfo(
title="Oops",
message="Please make sure you haven't left any fields empty."
)
else:
try:
with open("data.json", "r") as data_file:
data = json.load(data_file)
except FileNotFoundError:
with open("data.json", "w") as data_file:
json.dump(new_data, data_file, indent=4)
else:
data.update(new_data)
with open("data.json", "w") as data_file:
json.dump(data, data_file, indent=4)
finally:
website_entry.delete(0, END)
password_entry.delete(0, END)
def find_password():
website = website_entry.get()
try:
with open("data.json") as data_file:
data = json.load(data_file)
except FileNotFoundError:
messagebox.showinfo(title="Error", message="No Data File Found.")
else:
if website in data:
email = data[website]["email"]
password = data[website]["password"]
messagebox.showinfo(title=website, message=f"Email: {email}\nPassword: {password}")
else:
messagebox.showinfo(title="Error", message=f"No details for {website} exists.")
# UI SETUP
window = Tk()
window.title("Password Manager")
window.config(padx=50, pady=50)
canvas = Canvas(width=200, height=200)
logo_img = PhotoImage(file="logo.png")
canvas.create_image(100, 100, image=logo_img)
canvas.grid(column=0, row=0, columnspan=3)
# Labels
website_label = Label(text="Website:")
website_label.grid(column=0, row=1)
email_label = Label(text="Email/Username:")
email_label.grid(column=0, row=2)
password_label = Label(text="Password:")
password_label.grid(column=0, row=3)
# Entries
website_entry = Entry(width=20)
website_entry.grid(column=1, row=1)
website_entry.focus()
email_entry = Entry(width=38)
email_entry.grid(column=1, row=2, columnspan=2)
email_entry.insert(0, "angela@gmail.com")
password_entry = Entry(width=20)
password_entry.grid(column=1, row=3)
# Buttons
search_button = Button(text="Search", width=16, command=find_password)
search_button.grid(row=1, column=2)
generate_button = Button(text="Generate Password", width=16, command=generate_password)
generate_button.grid(column=2, row=3)
add_button = Button(text="Add", width=38, command=save)
add_button.grid(column=1, row=4, columnspan=2)
window.mainloop()