python自带库sys关于python解释器操作

sys 库简介

Python 的 sys 库提供了访问和控制Python解释器的接口。它允许程序与Python解释器交互，如获取命令行参数、管理解释器的运行环境、输出错误信息等。sys 还可以用来执行外部命令、控制标准输入输出和缓冲区大小。这个库在系统编程、脚本开发和调试工具中非常有用，提供了强大的运行时控制能力。

sys库 python解释器操作

from pandas import pd
import time
import sys
import os
# 打印覆盖
for i in range(5):
    # print (i,end="")
    sys.stdout.write("/r %s" % i)
    sys.stdout.flush()
    time.sleep(1)
# 查看包
print (sys.modules)  # 打印，查看该字典具体内容。
print ("当前平台")
print (sys.platform)
# win32
print ("当前Python版本")
print (sys.version)
# 3.6.8 (tags/v3.6.8:3c6b436a57, Dec 24 2018, 00:16:47) [MSC v.1916 64 bit (AMD64)]
print ("默认编码格式")
print (sys.getdefaultencoding())
# utf-8
print ("所有系统模块")
print (sys.modules)
# {"builtins": <module "builtins" (built-in)>, 
# "sys": <module "sys" (built-in)>, 
# "_frozen_importlib": <module "_frozen_importlib" (frozen)>, 
# "_imp": <module "_imp" (built-in)>, 
# "_warnings": <module "_warnings" (built-in)>, 
# "_thread": <module "_thread" (built-in)>, 
# "_weakref": <module "_weakref" (built-in)>, 
# "_frozen_importlib_external": <module "_frozen_importlib_external" (frozen)>, 
# "_io": <module "io" (built-in)>, 
# "marshal": <module "marshal" (built-in)>, 
# "nt": <module "nt" (built-in)>, "winreg": <module "winreg" (built-in)>, 
# "zipimport": <module "zipimport" (built-in)>, 
# "encodings": <module "encodings" from "C:Python36libencodings\__init__.py">, 
# "codecs": <module "codecs" from "C:Python36libcodecs.py">, 
# "_codecs": <module "_codecs" (built-in)>, 
# "encodings.aliases": <module "encodings.aliases" from "C:Python36libencodingsaliases.py">, 
# "encodings.utf_8": <module "encodings.utf_8" from "C:Python36libencodingsutf_8.py">, 
# "_signal": <module "_signal" (built-in)>, 
# "__main__": <module "__main__" from "pp.py">, 
# "encodings.latin_1": <module "encodings.latin_1" from "C:Python36libencodingslatin_1.py">, 
# "io": <module "io" from "C:Python36libio.py">, 
# "abc": <module "abc" from "C:Python36libabc.py">, 
# "_weakrefset": <module "_weakrefset" from "C:Python36lib\_weakrefset.py">, 
# "site": <module "site" from "C:Python36libsite.py">, 
# "os": <module "os" from "C:Python36libos.py">, 
# "errno": <module "errno" (built-in)>, 
# "stat": <module "stat" from "C:Python36libstat.py">, 
# "_stat": <module "_stat" (built-in)>, 
# "ntpath": <module "ntpath" from "C:Python36libtpath.py">, 
# "genericpath": <module "genericpath" from "C:Python36libgenericpath.py">, 
# "os.path": <module "ntpath" from "C:Python36lib    path.py">, 
# "_collections_abc": <module "_collections_abc" from "C:Python36lib\_collections_abc.py">, 
# "_sitebuiltins": <module "_sitebuiltins" from "C:Python36lib\_sitebuiltins.py">, 
# "sysconfig": <module "sysconfig" from "C:Python36libsysconfig.py">}
print ("导入模块及包的查找路径")
print (sys.path)
# ["C:UsersxxxDesktoppy", 
# "C:Python36python36.zip", 
# "C:Python36DLLs", 
# "C:Python36lib", 
# "C:Python36", 
# "C:Python36libsite-packages"]
a = os.path.abspath(__file__)     # 当前文件绝对路径
BASE_DIR = os.path.dirname(a)     # 存放c.py所在的绝对路径
sys.path.append(BASE_DIR)         # 可以加路径
# 脚本后参数
# 用以下命令启动
# python demo.py hello
print ("脚本路径", sys.argv[0])
if len(sys.argv) > 1:
    print ( "脚本后参数为", sys.argv[1:])
else:
    print ("无参数")
# 脚本后参数为 ["hello"]