complete argparse

tinylambda · tinylambda · commit d4b52331aa05 · 2021-07-09T13:04:57.000+08:00
diff --git a/module_argparse/argparse_FileType.py b/module_argparse/argparse_FileType.py
@@ -0,0 +1,18 @@
+import argparse
+
+parser = argparse.ArgumentParser()
+parser.add_argument('-i', metavar='in-file', type=argparse.FileType('rt'))
+parser.add_argument('-o', metavar='out-file', type=argparse.FileType('wt'))
+
+try:
+    results = parser.parse_args()
+    print('input file: ', results.i)
+    print('output file: ', results.o)
+except IOError as msg:
+    parser.error(str(msg))
+
+# python argparse_FileType.py -h
+# python argparse_FileType.py -i argparse_FileType.py
+# python argparse_FileType.py -i argparse_FileType.py -o /tmp/file.txt
+# python argparse_FileType.py -i nosuchfile.txt
+
diff --git a/module_argparse/argparse_choices.py b/module_argparse/argparse_choices.py
@@ -0,0 +1,10 @@
+import argparse
+
+parser = argparse.ArgumentParser()
+parser.add_argument('--mode', choices=('read-only', 'read-write'))
+print(parser.parse_args())
+
+# python argparse_choices.py -h
+# python argparse_choices.py --mode read-only
+# python argparse_choices.py --mode invlaid
+
diff --git a/module_argparse/argparse_custom_action.py b/module_argparse/argparse_custom_action.py
@@ -0,0 +1,33 @@
+import argparse
+
+
+class CustomAction(argparse.Action):
+    def __init__(self, *args, **kwargs):
+        argparse.Action.__init__(self, *args, **kwargs)
+        print('initializing customAction')
+        for name, value in sorted(locals().items()):
+            if name == 'self' or value is None:
+                continue
+            print('\t{} = {!r}'.format(name, value))
+        print()
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        print('Processing customAction for {}'.format(self.dest))
+        print('\tparser = {}'.format(id(parser)))
+        print('\tvalues = {!r}'.format(values))
+        print('\toption_string = {!r}'.format(option_string))
+
+        if isinstance(values, list):
+            values = [v.upper() for v in values]
+        else:
+            values = values.upper()
+        setattr(namespace, self.dest, values)
+        print()
+
+
+parser = argparse.ArgumentParser()
+parser.add_argument('-a', action=CustomAction)
+parser.add_argument('-m', nargs='*', action=CustomAction)
+results = parser.parse_args(['-a', 'value', '-m', 'multivalue', 'second'])
+print(results)
+
diff --git a/module_argparse/argparse_nargs.py b/module_argparse/argparse_nargs.py
@@ -0,0 +1,17 @@
+import argparse
+
+parser = argparse.ArgumentParser()
+parser.add_argument('--three', nargs=3)
+parser.add_argument('--optional', nargs='?')
+parser.add_argument('--all', nargs='*', dest='all')
+parser.add_argument('--one-or-more', nargs='+')
+
+print(parser.parse_args())
+
+# python argparse_nargs.py -h
+# python argparse_nargs.py --three <- error
+# python argparse_nargs.py --three a b c
+# python argparse_nargs.py --optional with_value
+# python argparse_nargs.py --one-or-more  <- error
+# python argparse_nargs.py --one-or-more with multiple values
+
diff --git a/module_argparse/argparse_type.py b/module_argparse/argparse_type.py
@@ -0,0 +1,17 @@
+import argparse
+
+parser = argparse.ArgumentParser()
+parser.add_argument('-i', type=int)
+parser.add_argument('-f', type=float)
+parser.add_argument('--file', type=open)
+
+try:
+    print(parser.parse_args())
+except IOError as msg:
+    parser.error(str(msg))
+
+# python argparse_type.py -i 100
+# python argparse_type.py -f 100
+# python argparse_type.py --file /tmp/a.log
+# python argparse_type.py --file argparse_type.py
+
