student_data = {
"name":"inderpaal",
"age":21,
"course":['Bsc', 'Computer Science']
}
#the keys are the left hand side and the values are the right hand side
#to print data you do print(name_of_dictionary['key_name'])
print(student_data['name']) # will print 'inderpaal'
print(student_data['age']) # will print 21
print(student_data['course'])[0]
#this will print 'Bsc' since that field is an array and array[0] is 'Bsc'
<view> = <dict>.keys() # Coll. of keys that reflects changes.
<view> = <dict>.values() # Coll. of values that reflects changes.
<view> = <dict>.items() # Coll. of key-value tuples that reflects chgs.
value = <dict>.get(key, default=None) # Returns default if key is missing.
value = <dict>.setdefault(key, default=None) # Returns and writes default if key is missing.
<dict> = collections.defaultdict(<type>) # Creates a dict with default value of type.
<dict> = collections.defaultdict(lambda: 1) # Creates a dict with default value 1.
<dict> = dict(<collection>) # Creates a dict from coll. of key-value pairs.
<dict> = dict(zip(keys, values)) # Creates a dict from two collections.
<dict> = dict.fromkeys(keys [, value]) # Creates a dict from collection of keys.
<dict>.update(<dict>) # Adds items. Replaces ones with matching keys.
value = <dict>.pop(key) # Removes item or raises KeyError.
{k for k, v in <dict>.items() if v == value} # Returns set of keys that point to the value.
{k: v for k, v in <dict>.items() if k in keys} # Returns a dictionary, filtered by keys.
#dictionary
programming = {
"Bugs": "These are the places of code which dose not let your program run successfully"
,"Functions":"This is a block in which you put a peice of code"
,"shell":"This is a place where the code is exicuted"
}
print(programming["Bugs"])
print(programming["shell"])
#error
#print(programming["pugs"])
# Dictionaries in Python are used to store set of data like Key: Value pair
# the syntax of a dictionary in Python is very simple we use {} inside that
# we define {Key: Value}, to separate multiple values we use','
programming_dictionary = {
"Bug": "An error in a program that prevents the program from running as expected.",
"Function": "A piece of code that you can easily call over and over again.",
"Loop": "The action of doing sommething again and again",
}
# to retrieve the values from a dictionary we use the Key name as an Index
# retrieving the Function's definition
print(programming_dictionary["Function"]) # this will print the definition of Function
# if you wanna print all the entries in the dictionary you can do that by for loop
for key in programming_dictionary:
print(programming_dictionary[key]) # prints all entries
# adding items to a dictionary
# the following code will add another entry to the dictionary called Variable
programming_dictionary["Variable"] = "The label to store some sort of data"
print(programming_dictionary["Variable"])
# editing the values of a key
# editing the value of variable
programming_dictionary["Variable"] = "Variables are nothing but reserved memory locations to store values. This means that when you create a variableyou reserve some space in memory"
# if you learnt something from this please upvote it
# Dictionaries in Python
ages = {"John": 43, "Bob": 24, "Ruth": 76} # Marked by { at beginning and a } at end
# ^^^ Has sets of keys and values, like the 'John' and 43 set. These two values must be seperated by a colon
# ^^^ Sets of values seperated by commas.
#A dictionary has key-value pairs. Here 1,2,3 are the keys and Item1,Item2,Item3
#are their values respectively.
dictionaryName = { 1: "Item1", 2: "Item2", 3: "Item3"}
#retrieving value of a particular key
dictionaryName[1]
#retrieving all the keys in a dictionary
dictionaryName.keys()
#retrieving all the values in a dictionary
dictionaryName.values()
#a dictionary
dict = {
"key": "value",
"other_key": "value"
}
#get a value from the dictionary using the key
print(dict["key"])
#you can also get a value from the dictionary using a normal index:
print(dict[1])
# A dict (dictionary) is a data type that store keys/values
myDict = {"name" : "bob", "language" : "python"}
print(myDict["name"])
# Dictionaries can also be multi-line
otherDict {
"name" : "bob",
"phone" : "999-999-999-9999"
}
#Python dictionaries consists of key value pairs tha
#The following is an example of dictionary
state_capitals = {
'Arkansas': 'Little Rock',
'Colorado': 'Denver',
'California': 'Sacramento',
'Georgia': 'Atlanta'
}
#Adding items to dictionary
#Modification of the dictionary can be done in similar maner
state_capitals['Kampala'] = 'Uganda' #Kampala is the key and Uganda is the value
#Interating over a python dictionary
for k in state_capitals.keys():
print('{} is the capital of {}'.format(state_capitals[k], k))