Recursive invocation of the python-function

the recursive invocation, as the name implies, calls the function inside the function (calling itself), usually using it to calculate factorial, accumulate, etc.Note:-Must have the final default resultIf n ==0, (cannot always call itself if there is no possibility of causing a dead loop)-Recursive parameters must converge to the default resultfunc (n-1)  Example 1: Calculate factorial of 5

# !/usr/bin/env python def func (n): if n = = 0:  return 1 else:  return N * func (n-1 
   
    print func (5)
   

 Example 2: Calculation of 1 to 100 and

# !/usr/bin/env python def  = 0  if n = = 0:  return  0  Else:  retur N N + func (n-1print func (100)

Example 3: Print all file names in the directory in a recursive way

# !/usr/bin/env python Import OS Import  def      = Os.listdir (n) for in Lsdir: if Os.path.isfile (Os.path.join (n,i)): Print Os.path.join (n,i) Else : Listdir (Os.path.join (n,i)) Listdir (sys.argv[1])

Improved version:

#!/usr/bin/env python ImportOSImportSYSdefprint_file (path): Lsdir=os.listdir (path) files= [I forIinchLsdirifOs.path.isfile (Os.path.join (path,i))] Dicts= [I forIinchLsdirifOs.path.isdir (Os.path.join (path,i))]ifFiles: forIinchFiles:PrintOs.path.join (path,i)ifdicts: forFinchDicts:print_file (Os.path.join (path,f)) Print_file (sys.argv[1])

modules usedOs.pass.isdir ()-Determine if the following file is a directory, if yes returns True (cannot determine if the directory exists, does not exist and will return false)Os.path.isfile ()-To determine if the file that follows is a file, yes to return true (cannot determine if the file exists, does not exist and will return false)Os.path.join ()-connect the path in parentheses (file)os.path.join ('/etc/', ' passwd ', ' abc ')---->/ETC/PASSWD/ABC NotePython3 The default recursion depth cannot exceed 100 levels 

Recursive invocation of the python-function