课程进度 77% · 第9/11章第9/11章 · 标签 1/2
— 1 —
日期与时间
```python
# datetime 模块
from datetime import datetime, timedelta, date
now = datetime.now()
print(now.strftime("%Y-%m-%d %H:%M:%S"))
today = date.today()
yesterday = today - timedelta(days=1)
# 字符串解析
dt = datetime.strptime("2024-01-01", "%Y-%m-%d")
# time 模块
import time
print(time.time()) # 时间戳
time.sleep(1) # 延迟1秒
# calendar 模块
import calendar
print(calendar.month(2024, 1)) # 月历
```
python
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# datetime 模块
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from datetime import datetime, timedelta, date
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now = datetime.now()
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print(now.strftime("%Y-%m-%d %H:%M:%S"))
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today = date.today()
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yesterday = today - timedelta(days=1)
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# 字符串解析
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dt = datetime.strptime("2024-01-01", "%Y-%m-%d")
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# time 模块
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import time
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print(time.time()) # 时间戳
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time.sleep(1) # 延迟1秒
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# calendar 模块
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import calendar
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print(calendar.month(2024, 1)) # 月历
◆
数学与随机数
```python import math import random print(math.pi) # 3.141592653589793 print(math.sqrt(16)) # 4.0 print(math.floor(3.7)) # 3 print(math.ceil(3.2)) # 4 print(random.randint(1, 10)) print(random.choice(["a", "b", "c"])) random.shuffle(lst) ```
python
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import math
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import random
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print(math.pi) # 3.141592653589793
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print(math.sqrt(16)) # 4.0
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print(math.floor(3.7)) # 3
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print(math.ceil(3.2)) # 4
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print(random.randint(1, 10))
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print(random.choice(["a", "b", "c"]))
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random.shuffle(lst)
— 2 —
系统与序列化
```python
import os
import sys
import json
import pickle
# os 模块
print(os.getcwd()) # 当前目录
print(os.listdir(".")) # 文件列表
print(os.environ) # 环境变量
# sys 模块
print(sys.version) # Python版本
print(sys.argv) # 命令行参数
sys.exit(0) # 退出程序
# JSON 序列化
data = {"name": "Alice", "age": 30}
json_str = json.dumps(data, ensure_ascii=False)
parsed = json.loads(json_str)
print(parsed["name"])
# pickle 序列化
with open("data.pkl", "wb") as f:
pickle.dump(data, f)
with open("data.pkl", "rb") as f:
loaded = pickle.load(f)
```
python
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import os
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import sys
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import json
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import pickle
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# os 模块
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print(os.getcwd()) # 当前目录
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print(os.listdir(".")) # 文件列表
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print(os.environ) # 环境变量
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# sys 模块
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print(sys.version) # Python版本
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print(sys.argv) # 命令行参数
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sys.exit(0) # 退出程序
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# JSON 序列化
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data = {"name": "Alice", "age": 30}
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json_str = json.dumps(data, ensure_ascii=False)
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parsed = json.loads(json_str)
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print(parsed["name"])
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# pickle 序列化
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with open("data.pkl", "wb") as f:
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pickle.dump(data, f)
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with open("data.pkl", "rb") as f:
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loaded = pickle.load(f)