Python os.nice()用法及代碼示例

Python中的OS模塊提供了與操作係統進行交互的函數。操作係統屬於Python的標準實用程序模塊。該模塊提供了使用依賴於操作係統的函數的便攜式方法。

如果文件名和路徑無效或無法訪問，或者具有正確類型但操作係統不接受的其他參數，則os模塊中的所有函數都會引發OSError。

os.nice()Python中的方法用於按指定的值增加流程的美觀程度。

當進程要獲取CPU時間以執行其工作時，nice或nice值是CPU遵循的一組準則。處理的好壞範圍在-20到19(包括兩者)之間。具有較低niceness或nice值的進程將被賦予較高的優先級和更多的CPU時間，而具有較高nice值的進程將被賦予較低的優先級和更少的CPU時間。

注意： os.nice()該方法僅在UNIX平台上可用。任何用戶都可以提高流程的美觀度，但是隻有超級用戶才能降低流程的美觀度。
超級用戶是指具有運行或執行操作係統中所有程序的所有權限的root用戶或管理用戶。

用法： os.nice(value)

參數:
value：一個整數值。
該過程的新舒適度將被計算為新的舒適度=先前的舒適度+指定值

返回類型：此方法返回一個整數值，該整數值表示該過程的新特性。

代碼1：使用os.nice()方法來提高流程的美觀度

# Python program to explain os.nice() method  
  
# importing os module  
import os 
  
  
# Get the current nice value 
# of the process 
niceValue = os.nice(0) 
  
# Print the current nice value  
# of the process 
print("Current nice value of the process:", niceValue) 
  
# Increase the niceness  
# of the process 
value = 5
niceValue = os.nice(value) 
print("\nNiceness of the process increased") 
  
# Print the current nice value  
# of the process 
print("\nCurrent nice value of the process:", niceValue) 
  
  
# Increase the niceness  
# of the process 
value = 10
niceValue = os.nice(value) 
print("\nNiceness of the process increased") 
  
# Print the current nice value  
# of the process 
print("\nCurrent nice value of the process:", niceValue) 
  
  
# Increase the niceness  
# of the process 
value = 10
niceValue = os.nice(value) 
print("\nNiceness of the process increased") 
  
# Print the current nice value  
# of the process 
print("\nCurrent nice value of the process:", niceValue) 
  
  
# The maximum possible niceness of a process 
# can be 19 so if niceness to be set exceeds 
# the maximum limit then it will set to  
# the maximum possible niceness i.e 19

輸出：

Current nice value of the process: 0

Niceness of the process increased

Current nice value of the process: 5

Niceness of the process increased

Current nice value of the process: 15

Niceness of the process increased

Current nice value of the process: 19

代碼2：使用os.nice()方法降低流程的美觀程度

# Python program to explain os.nice() method  
  
# importing os module  
import os 
  
  
# Note : Only a superuser can 
# decrease a process's niceness 
# so run the program as superuser 
# to avoid permission related error 
  
# Get the current nice value 
# of the process 
niceValue = os.nice(0) 
  
# Print the Current nice value  
# of the process 
print("Current nice value of the process:", niceValue) 
  
# Decrease the niceness  
# of the process 
value = -5
niceValue = os.nice(value) 
print("\nNiceness of the process decreased") 
  
# Print the current nice value  
# of the process 
print("\nCurrent nice value of the process:", niceValue) 
  
# Decrease the niceness  
# of the current process 
value = -10
niceValue = os.nice(value) 
print("\nNiceness of the process decreased") 
  
# Print the current nice value  
# of the process 
print("\nCurrent nice value of the process:", niceValue) 
  
  
# Decrease the niceness  
# of the current process 
value = -15
niceValue = os.nice(value) 
print("\nNiceness of the process decreased") 
  
# Print the current nice value  
# of the process 
print("\nCurrent nice value of the process:", niceValue) 
  
  
# The minimum possible niceness of a process 
# can be -20 so if niceness to be set is  
# lower than the minimum limit then 
# it will set to the minimum possible 
# niceness i.e -20

輸出：

Current nice value of the process: 0

Niceness of the process decreased

Current nice value of the process: -5

Niceness of the process decreased

Current nice value of the process: -15

Niceness of the process decreased

Current nice value of the process: -20

相關用法

注：本文由純淨天空篩選整理自ihritik大神的英文原創作品 Python | os.nice() method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。