Update examples

Author: nixuser

command_line_args/01_argv.py

@@ -0,0 +1,13 @@
+"""
+Usage:
+python3 01_argv.py
+python3 01_argv.py a b c
+python3 01_argv.py "aaa aaad" abc
+"""
+import sys
+
+print(sys.argv[0])
+print(len(sys.argv))
+for arg in sys.argv:
+    print(arg)
+

command_line_args/02_arguments.py

@@ -0,0 +1,8 @@
+"""
+python3 02_arguments.py
+python3 02_arguments.py --help
+python3 02_arguments.py --abc
+"""
+import argparse
+parser = argparse.ArgumentParser()
+parser.parse_args()

command_line_args/03_args.py

@@ -0,0 +1,14 @@
+"""
+python3 03_args.py -h
+python3 03_args.py --dir /etc/
+python3 03_args.py -v --dir test_dir
+"""
+import argparse
+parser = argparse.ArgumentParser()
+parser.add_argument("--dir", help="Directory to list files")
+parser.add_argument("-v", "--verbosity", help="increase output verbosity", 
+                    action="store_true")
+args = parser.parse_args()
+print(args.dir)
+print(args.verbosity)
+

command_line_args/4913

@@ -0,0 +1,30 @@
+"""
+Usage examples:
+python3 ./01_stat.py ../read_from_stdin/
+python3 ./01_stat.py /dev/
+"""
+import os, sys
+from stat import *
+
+def walktree(top, callback):
+    '''recursively descend the directory tree rooted at top,
+       calling the callback function for each regular file'''
+
+    for f in os.listdir(top):
+        pathname = os.path.join(top, f)
+        mode = os.lstat(pathname).st_mode
+        if S_ISDIR(mode):
+            # It's a directory, recurse into it
+            walktree(pathname, callback)
+        elif S_ISREG(mode):
+            # It's a file, call the callback function
+            callback(pathname)
+        else:
+            # Unknown file type, print a message
+            print('Skipping %s' % pathname)
+
+def visitfile(file):
+    print('visiting', file)
+
+if __name__ == '__main__':
+    walktree(sys.argv[1], visitfile)

command_line_args/5036

@@ -0,0 +1,9 @@
+from pathlib import Path
+
+tmp_dir = Path('/etc/')
+for fileobj in tmp_dir.glob('*.conf'):
+    print(f'{fileobj.name} : ', end='')
+
+    with fileobj.open('r') as data_file:
+        data = data_file.readline().rstrip()
+        print(data)

filesystem/01_stat.py

@@ -0,0 +1,8 @@
+import os
+
+directory = "/var"
+for root, dirs, files in os.walk("/var"):
+   #for name in files:
+   #   print(os.path.join(root, name))
+   for name in dirs:
+      print(os.path.join(root, name))

filesystem/02_globexample.py

@@ -0,0 +1,7 @@
+import os
+
+path = '/home/vagrant'
+with os.scandir(path) as it:
+    for entry in it:
+        if entry.name.startswith('.') and entry.is_file():
+            print(entry.name)

filesystem/list_files_walk.py

@@ -0,0 +1,13 @@
+"""
+Usage examples:
+echo test_string | python3 01_sys_stdin.py
+yes | head -10 | python3 01_sys_stdin.py
+python3 01_sys_stdin.py < 01_sys_stdin.py
+"""
+
+import sys
+
+
+for line in sys.stdin:
+    print(line.strip())
+