dict python

#Creating dictionaries
dict1 = {'color': 'blue', 'shape': 'square', 'volume':40}
dict2 = {'color': 'red', 'edges': 4, 'perimeter':15}

#Creating new pairs and updating old ones
dict1['area'] = 25 #{'color': 'blue', 'shape': 'square', 'volume': 40, 'area': 25}
dict2['perimeter'] = 20 #{'color': 'red', 'edges': 4, 'perimeter': 20}

#Accessing values through keys
print(dict1['shape'])

#You can also use get, which doesn't cause an exception when the key is not found
dict1.get('false_key') #returns None
dict1.get('false_key', "key not found") #returns the custom message that you wrote 

#Deleting pairs
dict1.pop('volume')

#Merging two dictionaries
dict1.update(dict2) #if a key exists in both, it takes the value of the second dict
dict1 #{'color': 'red', 'shape': 'square', 'area': 25, 'edges': 4, 'perimeter': 20}

#Getting only the values, keys or both (can be used in loops)
dict1.values() #dict_values(['red', 'square', 25, 4, 20])
dict1.keys() #dict_keys(['color', 'shape', 'area', 'edges', 'perimeter'])
dict1.items() 
#dict_items([('color', 'red'), ('shape', 'square'), ('area', 25), ('edges', 4), ('perimeter', 20)])

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'

#title			:Dictionary Example
#author         :Josh Cogburn
#date           :20191127
#github         :https://github.com/josh-cogburn
#====================================================

thisdict = {
	"brand": "Ford",
 	"model": "Mustang",
 	"year": 1964
}

#Assigning a value
thisdict["year"] = 2018

# dictionary refresh


new_dict = {
    "first":"1,2,3",
    "second":"321",
    "third":"000",
}


# adding to dictionary
new_dict.update({"fourth":"D"})
print(new_dict)

#removing from dictionary
new_dict.pop("first")
print(new_dict)


new = {"five":"888"}
#updating a dictionary
new_dict.update(new)
print(new_dict)

<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.

l = {"a":"aaaaa"}
print(l["a"])
#aaaa

l = [{"a":"aaaaa"}, {"a":"AAA65675765"}]
print(l[0]["a"])
#aaaa

human = {
  "code": "Python",
  "name": "John",
  "age": 32
}

print(human["age"])
#32 :D

thisdict =	{
  "brand": "Ford",
  "model": "Mustang",
  "year": 1964
}
x = thisdict["model"]
print(x)
---------------------------------------------------------------------------
Mustang

dictionary = {
    "name": "Elie",
    "family name": "Carcassonne",
    "date of born": "01/01/2001",
    "list": ["hey", "hey"]
}

# Creating an empty Dictionary
Dict = {}
print("Empty Dictionary: ")
print(Dict)
 
# Creating a Dictionary
# with dict() method
Dict = dict({1: 'Geeks', 2: 'For', 3:'Geeks'})
print("\nDictionary with the use of dict(): ")
print(Dict)
 
# Creating a Dictionary
# with each item as a Pair
Dict = dict([(1, 'Geeks'), (2, 'For')])
print("\nDictionary with each item as a pair: ")
print(Dict)

txt = "this is a wild string"

print(txt.replace("i", "x"))  # print string with all i characters replaced with x
print(txt.replace("i", "x", 2))  # print string with first two i characters found with x
print(txt.upper())  # print string in all uppercase letters
print(txt.lower())  # print string in all uppercase letters

print(ord('A'))  # print the ordinal value of a character
print(chr(95))  # print character from its ordinal value
print('Yes' * 5) # print string Yes 5 times

# Reference strings by index
print(txt[0])  # print first letter of string from starting index
print(txt[0:2])  # print first two letters from starting index
print(txt[1:])  # print all characters except the first letter
print(txt[0::2])  # print every second character
print(txt[::-1])  # print string in reverse
print(txt[-1])  # print the last character in a string
print(txt[-2:])  # print the last who characters in a string

# check if a wild is found in txt
if "wild" in txt:
  print("wild is found in txt")

# check if a blah is not found in txt
if "blah" not in txt:
  print("is not found in txt")

# Check if txt starts with this
if txt.startswith("this"):
  print("Starts with this")

# check if txt ends with ing
if txt.endswith("ing"):
  print("Ends with ing")

# Split a string into a tuple when the delimiter is first encountered
txt = 'random-data'

data_split = txt.partition('-')
print(data_split)
# output ('random', '-', 'data')

len(txt)  # Return length of string

# loop through each character in string
for char in txt:
  print(char)

# Display price with commas and 2 digit precision
price = 9749000
display_price = f"My price {price:,.2f}"
print(display_price)


fruits = ['orange', 'apple', 'pear', 'banana', 'kiwi', 'apple', 'banana']
fruits.count('apple')  # count number of apples found in list
# output 2
fruits.count('tangerine')  # count number of tangerines in list
# output 0
fruits.index('banana')  # find the first index of banana
# output 3
fruits.index('banana', 4)  # Find next banana starting a position 4
# output 6
fruits.reverse()  # reverse fruits array
fruits
# output ['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange']
fruits.append('grape')  # append grape at the end of array
fruits
# output ['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange', 'grape']
fruits.sort()
fruits
# output ['apple', 'apple', 'banana', 'banana', 'grape', 'kiwi', 'orange', 'pear']

len(fruits)  # length of fruits array
# output 8

# loop and print each fruit
for fruit in fruits:
  print(fruit)
  
empty_set = set()

basket = {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'}
print(basket)                      # show that duplicates have been removed
# output {'orange', 'banana', 'pear', 'apple'}

# check if orange is in basket set
print('orange' in basket)
# output true

# convert a string to a set of letters - sets contains no duplicates
set_a = set('abcd')
set_b = set('bcde')

# the operations below returns new sets
# print letters in set_a but not in set_b - difference
print(set_a - set_b)
# output {'a'}

# print set letters that is in either set a or b - union
print(set_a | set_b)
# output {'a', 'c', 'e', 'b', 'd'}

# print letters that are in both set_a and set_b - intersection
print(set_a & set_b)
# output {'c', 'd', 'b'}

# print letters that are in set_a and set_b when the letters are found in a set but no the other set - symmetric_difference()
print(set_a ^ set_b)
# output {'a', 'e'}

# Creating dictionaries
dict1 = {'color': 'blue', 'shape': 'square', 'volume': 40}
dict2 = {'color': 'red', 'edges': 4, 'perimeter': 15}

# Creating new pairs and updating old ones
dict1['area'] = 25  # {'color': 'blue', 'shape': 'square', 'volume': 40, 'area': 25}
dict2['perimeter'] = 20  # {'color': 'red', 'edges': 4, 'perimeter': 20}

# Accessing values through keys - an KeyError will occur if the key does not exists
print(dict1['shape'])

# You can also use get, which doesn't cause an exception when the key is not found
dict1.get('false_key')  # returns None
dict1.get('false_key', "key not found")  # returns the custom message that you wrote

# Delete item key and return the value if the key does not exists a KeyError occurs
print(dict1.pop('volume'))

# Merging two dictionaries
dict1.update(dict2)  # if a key exists in both, it takes the value of the second dict
dict1  # {'color': 'red', 'shape': 'square', 'area': 25, 'edges': 4, 'perimeter': 20}

# Getting only the values, keys or both (can be used in loops)
dict1.values()  # dict_values(['red', 'square', 25, 4, 20])
dict1.keys()  # dict_keys(['color', 'shape', 'area', 'edges', 'perimeter'])
dict1.items()
# dict_items([('color', 'red'), ('shape', 'square'), ('area', 25), ('edges', 4), ('perimeter', 20)])

# create a shallow copy of dict1
dict3 = dict1.copy()
# dict3 = {'color': 'red', 'shape': 'square', 'area': 25, 'edges': 4, 'perimeter': 20}

a = {'a': 123, 'b': 'test'}

mydictionary = {'name':'python', 'category':'programming', 'topic':'examples'}

for x in mydictionary:
	print(x, ':', mydictionary[x])

# 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))

dict_name = {"key1": "value1", "key2": "value2", ...}

stationary_items = {
    "Pencil":"Pencil is used to write things in copy",
    "Eraser": "Eraser is used to remove the written things",
    "Sharpner":"This is used to sharp your pencil"
}
print(stationary_items["Pencil"])

thisdict = {
  "brand": "Ford",
  "model": "Mustang",
  "year": 1964
}
print(thisdict["brand"])

>>> d = {}
>>> d
{}
>>> d = {'dict': 1, 'dictionary': 2}
>>> d
{'dict': 1, 'dictionary': 2}

alien = {'color': 'green', 'points': 5}

# Create the "car" dictionary
car = {
  "make": "abc",
  "model": "def",
  "top_speed": 150,
}
# Print the top speed
print(car["top_speed"])
# Change the make
car["make"] = "ghi"

#Creating dictionaries
dict1 = {'color': 'blue', 'shape': 'square', 'volume':40}
dict2 = {'color': 'red', 'edges': 4, 'perimeter':15}

# Creating a Nested Dictionary
# as shown in the below image
Dict = {1: 'Geeks', 2: 'For',
        3:{'A' : 'Welcome', 'B' : 'To', 'C' : 'Geeks'}}
 
print(Dict)

>>> tel = {'jack': 4098, 'sape': 4139}
>>> tel['guido'] = 4127
>>> tel
{'jack': 4098, 'sape': 4139, 'guido': 4127}
>>> tel['jack']
4098
>>> del tel['sape']
>>> tel['irv'] = 4127
>>> tel
{'jack': 4098, 'guido': 4127, 'irv': 4127}
>>> list(tel)
['jack', 'guido', 'irv']
>>> sorted(tel)
['guido', 'irv', 'jack']
>>> 'guido' in tel
True
>>> 'jack' not in tel
False