Python基础代码大全

print("Hello, World!")

x = 10
y = "Hello"

if x > 5:
    print("x大于5")
elif x == 5:
    print("x等于5")
else:
    print("x小于5")

for i in range(5):
    print(i)
    
while x > 0:
    print(x)
    x -= 1

try:
    # 可能发生异常的代码
    result = 10 / 0
except ZeroDivisionError:
    # 处理异常的代码
    print("除数不能为零")

x = 10
y = 3.14
z = complex(1, 2)

s = "Hello, World!"
print(s[0])  # 输出第一个字符
print(s[7:12])  # 输出从第8个字符到第12个字符

lst = [1, 2, 3, 4, 5]
print(lst[0])  # 输出第一个元素
print(lst[2:4])  # 输出第3个元素到第4个元素

tpl = (1, 2, 3, 4, 5)
print(tpl[0])  # 输出第一个元素
print(tpl[2:4])  # 输出第3个元素到第4个元素

dic = {"name": "Tom", "age": 18}
print(dic["name"])  # 输出键为"name"的值
print(dic.keys())  # 输出所有键
print(dic.values())  # 输出所有值

s = {1, 2, 3, 4, 5}
s.add(6)  # 添加元素
s.remove(3)  # 移除元素

f = open("file.txt", "r")

content = f.read()
print(content)

f.write("Hello, World!")

f.close()

import math
print(math.sqrt(16))  # 输出平方根

import requests
response = requests.get("https://www.example.com")
print(response.text)  # 输出网页内容

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age
        
    def say_hello(self):
        print("Hello, I'm", self.name)
        
p = Person("Tom", 18)
p.say_hello()

class Student(Person):
    def __init__(self, name, age, grade):
        super().__init__(name, age)
        self.grade = grade
        
    def say_hello(self):
        print("Hello, I'm", self.name, "and I'm in grade", self.grade)
        
s = Student("Jerry", 16, 10)
s.say_hello()

import pandas as pd
df = pd.DataFrame({"name": ["Tom", "Jerry"], "age": [18, 16]})
print(df.head())

from flask import Flask
app = Flask(__name__)
@app.route("/")
def hello():
    return "Hello, World!"
if __name__ == "__main__":
    app.run()

from sklearn.linear_model import LinearRegression
model = LinearRegression()
model.fit(X, y)

from PIL import Image
im = Image.open("image.jpg")
im.show()