added csv_update.py

Signed-off-by: ABHIJIT SINHA <[email protected]>

Author: greyshell

core_concepts/test_dict.py

@@ -24,18 +24,18 @@ def main():
 
     # look up: method 1
     try:
-        dept = name_dept["no_key"]  # throws exception when the key is not found
+        dept = name_dept["alice"]  # throws exception when the key is not found
         print(f"{dept}")
     except KeyError as e:
         print(f"error: {e}")
 
     # look up: method 2
-    if "key" in name_dept:  # inefficient because it queries the dict twice
-        dept = name_dept["no_key"]
+    if "alice" in name_dept:
+        dept = name_dept["alice"]  # inefficient because it queries the dict twice
         print(f"{dept}")
 
     # look up: method 3 (recommended)
-    dept = name_dept.get("alice", "no_key")  # provides the support for default value
+    dept = name_dept.get("alice", "not found")  # provides the support for default value
     print(f"{dept}")
 
     # get all keys
@@ -51,7 +51,7 @@ def main():
 
     # print the dict: method 2
     for key in name_dept:  # __iter__() => iterates over the keys, similar to name_dept.keys()
-        print(f"{key}: {name_dept[key]}")
+        print(f"{key}: {name_dept[key]}")  # does not occurs the key not found
 
 
 if __name__ == '__main__':

core_concepts/tuple_hands-on.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+
+# author: greyshell
+# description: hands-on
+
+
+def main():
+    # tuple: a finite ordered squence of values
+
+    # create tuple
+    # tuple literals
+    tup = (1, 2, "abc")  # supports heterogeneous data types
+    tup0 = 1, 2, 3  # also supports without first bracket, all values are packed into a single tuple
+    print(type(tup0))
+
+    # build in tuple function
+    tup2 = tuple("abc")  # it accepts single argument of type iterable, this single parameter is optional
+    tup3 = tuple()  # creates an empty tuple
+
+    # create a tuple with exactly one element
+    tup4 = (1,)  # need to include a comma after first element
+
+    # tuple and string
+    # similarities: finite length, indexing and slicing
+    # differences: string can only contains chars but tuple can contain any kind of value
+    values = (0, 1, 2, 3, 4)
+    new_values = values[0:3]  # returns a tuple
+    print(new_values)
+
+    for n in new_values:  # tuples are iterable
+        print(n)
+
+    x, y = 10, 20  # example of tuple unpacking
+    # LHS and RHS should be matched else it will raise ValueError
+    # utility: returning multiple values from a function
+
+    # check the existance of a value using in operator
+    if 3 in values:
+        print("found")
+
+    # tuples are immutable like string and frozenset
+
+    t = (1, ['a', 'b'], 'word')
+    t[1][0] = 'x'  # changes the list value as it does not modify the 2nd obj - list address
+    print(t)
+
+
+if __name__ == '__main__':
+    main()