merge 2 dicts python code example

Example 1: python join dict

dict.update([other])

Example 2: join two dictionaries python

z = {**x, **y}

Example 3: python merge two dictionaries in a single expression

z = {**x, **y}  #python 3.5 and above

z = x | y    #python 3.9+ ONLY

def merge_two_dicts(x, y): # python 3.4 or lower
      z = x.copy()   # start with x's keys and values
      z.update(y)    # modifies z with y's keys and values & returns None
      return z

Example 4: merge two dict python 3

z = {**x, **y}

Example 5: merge two list of dictionaries python with string

import pandas as pd

l1 = [{'id': 9, 'av': 4}, {'id': 10, 'av': 0}, {'id': 8, 'av': 0}]
l2 = [{'id': 9, 'nv': 45}, {'id': 10, 'nv': 0}, {'id': 8, 'nv': 30}]

df1 = pd.DataFrame(l1).set_index('id')
df2 = pd.DataFrame(l2).set_index('id')
df = df1.merge(df2, left_index=True, right_index=True)
df.T.to_dict()
# {9: {'av': 4, 'nv': 45}, 10: {'av': 0, 'nv': 0}, 8: {'av': 0, 'nv': 30}}

Example 6: python join dict

def mergeDict(dict1, dict2):
   ''' Merge dictionaries and keep values of common keys in list'''
   dict3 = {**dict1, **dict2}
   for key, value in dict3.items():
       if key in dict1 and key in dict2:
               dict3[key] = [value , dict1[key]]
 
   return dict3
 
# Merge dictionaries and add values of common keys in a list
dict3 = mergeDict(dict1, dict2)
 
print('Dictionary 3 :')
print(dict3)