Answers for "dictionarys python"

python dictionary

#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)])

how to use dictionaries in python

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'

dictionary in python

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

dictionary in python

d = {'key1':'value1','key2':'value2'}
print(d) # to print full dictionary
l=d.keys
print(l)   # to print keys
b=d.values
print(b)#to print values in dictionary

python dictionary

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"])

how to print a value from a dictionary in python

dictionary={
  
    "Jeff":{
      	"lastname":"bobson",
        "age":55,
        "working":True
    },
  
    "James":{
      	"lastname":"Bobson",
        "age":34,
        "working":False
    }
}

# For a good format:

for i in dictionary:
    print(i, ":")
    for j in dictionary[i]:
        print("  ", j, ":", dictionary[i][j])
    print()
        

# Output:

Jeff :
   lastname : bobson
   age : 55
   working : True
   
James :
   lastname : Bobson
   age : 34
   working : False
    
# For just a quick reading:

for k, v in dictionary.items():
  print(k, v)
  
# Output: 

Jeff {'lastname': 'bobson', 'age': 55, 'working': True}
James {'lastname': 'Bobson', 'age': 34, 'working': False}