304_python_模块1

 模块

# jason模块

data_dict ={"name" : "alex", "age":30}
# data_dic_str = json.dumps(data_dict, ensure_ascii=False)
data_dic_str = json.dumps(data_dict)
print(data_dic_str, type(data_dic_str))  # <class 'str'>  #

data_dic_str2 = json.loads( data_dic_str)  #{"name": "alex", "age": 30} <class 'str'>
print(data_dic_str2, type(data_dic_str2))  # {'name': 'alex', 'age': 30} <class 'dict'>

# datetime

t2 = datetime.now()
print(t2, type(t2))  # 2022-02-28 15:51:36.889999 <class 'datetime.datetime'>

t3 = t2 - timedelta(hours= 3) #2022-02-28 12:51:36.889999
print(t3)

#time和datetime

时间戳 time 
datetime 类型
字符串类型 

# str - datetime - time

text = "2022-02-28 12:51:36"

date_time = datetime.strptime(text, "%Y-%m-%d %H:%M:%S")  # datetime 类型

time_time = date_time.timestamp()   # 转成 timestamp 
print(time_time)  # 1646023896.0


# time - datetime - str

v1 = time.time()
date_time2 = datetime.fromtimestamp(v1)  # 转成 datetime 
# print(date_time2, type(date_time2))  #2022-02-28 16:12:41.733975 <class 'datetime.datetime'>

date_time2_str = datetime.strftime(date_time2, "%Y-%m-%d %H:%M:%S")  # 转成 string  
print(date_time2_str, type(date_time2_str))    #2022-02-28 16:14:45 <class 'str'>

sys模块

sys.path.append  导入文件默认寻找的路径

sys.argv   获取脚本的参数 

python demo.py   x1  x2 
 import sys
  print(sys.argv)
  # ["demo.py"]
  # ["demo.py","x1","x2"

shutil模块

``python
import shutil

# 1. 删除文件夹
"""
path = os.path.join(base_path, 'xx')
shutil.rmtree(path)
"""

# 2. 拷贝文件夹（新建目录）
"""
import shutil

shutil.copytree('pearvideo', 'x1')
"""

# 3.拷贝文件
"""
shutil.copy('x1/1745129/cont-1745129-15791216_adpkg-ad_hd.mp4', 'xx')
"""

# 4.文件或文件夹重命名
"""
shutil.move("x.png","xxxx.png")
shutil.move("/Users/wupeiqi/PycharmProjects/CodeRepository/files","/Users/wupeiqi/PycharmProjects/CodeRepository/images")
"""

# 5. 压缩文件
"""
# base_name，压缩后的压缩包文件
# format，压缩的格式，例如："zip", "tar", "gztar", "bztar", or "xztar".
# root_dir，要压缩的文件夹路径
"""
shutil.make_archive(base_name=r'datafile',format='zip',root_dir=r'files')


# 6. 解压文件
"""
# filename，要解压的压缩包文件
# extract_dir，解压的路径
# format，压缩文件格式
"""
shutil.unpack_archive(filename=r'2021.zip', extract_dir='x2/x3/x4', format='zip')
```

subprocess模块

```python
import subprocess

res = subprocess.getoutput("ls")
print(res)

res = subprocess.check_output("ls -l", shell=True, cwd="/Users/wupeiqi/PycharmProjects/xxx/xxx/xxx")
res_string = res.decode('utf-8')
print(res_string)