FinishedTheBasics

LearnTheBasics/11_Dictionaries.py

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+# A dictionary is a data type similar to arrays, but works with keys and values instead of indexes. Each value stored in a dictionary can be accessed using a key, which is any type of object (a string, a number, a list, etc.) instead of using its index to address it.
+# For example, a database of phone numbers could be stored using a dictionary like this:
+
+phonebook = {}
+phonebook["John"] = 938477566
+phonebook["Jack"] = 938377264
+phonebook["Jill"] = 947662781
+print(phonebook)
+
+#Alternatively, a dictionary can be initialized with the same values in the following notation:
+phonebook = {
+    "John" : 938477566,
+    "Jack" : 938377264,
+    "Jill" : 947662781
+}
+print(phonebook)
+
+#Dictionaries can be iterated over, just like a list. However, a dictionary, unlike a list, does not keep the order of the values stored in it. To iterate over key value pairs, use the following syntax:
+for name, number in phonebook.items():
+    print("Phone number of %s is %d" % (name, number))
+
+#To remove a specified index, use either one of the following notations:
+del phonebook["John"]
+print(phonebook)
+
+phonebook["John"] = 938477566   #To add it back in
+
+#alternative solution:
+phonebook.pop("John")
+print(phonebook)
+
+# Exercise
+# Add "Jake" to the phonebook with the phone number 938273443, and remove Jill from the phonebook.
+
+phonebook = {  
+    "John" : 938477566,
+    "Jack" : 938377264,
+    "Jill" : 947662781
+}  
+# your code goes here
+phonebook["Jake"] = 938273443
+del phonebook["Jill"]
+
+# testing code
+if "Jake" in phonebook:  
+    print("Jake is listed in the phonebook.")
+    
+if "Jill" not in phonebook:      
+    print("Jill is not listed in the phonebook.")