For each value in 1 dictionary take keys and for those keys in 2 dictionary print difference in values for all specific pairs of keys

Question

It's my first time here so sorry if I'm not conforming to some unspoken rule of the community So i have a dictionary mydict

{'ENST00000309502': ['ADORA1'],
 'ENST00000337894': ['ADORA1'],
 'ENST00000618295': ['ADORA1'],
 'ENST00000380573': ['ADRA1A'],
 'ENST00000519229': ['ADRA1A'],
 'ENST00000337474': ['AVPR2'],
 'ENST00000358927': ['AVPR2'],
 'ENST00000370049': ['AVPR2'],
 'ENST00000216629': ['BDKRB1'],
 'ENST00000611804': ['BDKRB1']...}

And for each specific value, I need to take the keys which are keys in my second dictionary mydict2

{'ENST00000216629':['3.61','3.45','3.65'...]
'ENST00000255380':['3.1','3.05','3.15'...]
'ENST00000304421':['3.61','3.15','3.65'...]...}

And i need to find difference in values of mydict2 for each of the key for the same value in mydict and print result like this

mydict[value] mydict2[key1] mydict2[key2] difference(list of values)

ADORA1 ENST00000309502 ENST00000337894 [3.61,3.25,3.14]

I only need one combination of difference so only 1-2 not 2-1 for some values in mydict there are more than two keys. Sorry for the long post I'm new in programming and I know I need for if loop, but im not sure how to write it. Thanks in advance for whoever helps.

Answer 1

In order to loop through all possible values in mydict , we need a set of values in mydict . Assuming that each value (eg ['ADORA1']) is a list with one element , we can flatten the list and create the set of values using

set_of_values = {value[0] for value in mydict.values()}

Then, we need the list of mydict keys corresponding to each value. We can use list comprehension and create a new dictionary mapping each mydict value to the list of mydict keys.

reversed_dict = {v:[key for (key, value) in mydict.items() if value[0] == v] for v in set_of_values}

The rest is straightforward. For each key in reversed_dict, we can print the corresponding mydict keys and mydict2 values.

for (key, values) in reversed_dict.items():
    print(f'{key} {values[0]} {values[1]} {mydict2[values[0]]} {mydict2[values[1]]}')

This will print

ADORA1 ENST00000309502 ENST00000337894 [3.61,3.25,3.14, ...] ['3.1','3.05','3.15'...]

for example.

It is unclear what a difference of a list is. If you need set difference, you can use python set using, for example,

set1 = set(mydict2[values[0]])
set2 = set(mydict2[values[1]])
print(set1 - set2)

Answer 2

I'm assuming you are looking for something like this:

# Loop over the "values" in mydict1 (i.e. the string in the value)
for value in {value[0] for value in mydict1.values()}:
    
    # Find the keys in mydict1 that correspond to the selected value
    keys = tuple(key for key in mydict1 if mydict1[key] == [value])

    # Loop over pairs of distinct keys
    num_of_keys = len(keys)
    for key1, key2 in {(keys[i], keys[j])
                       for i in range(num_of_keys)
                       for j in range(i+1, num_of_keys)}:

        # Check if both keys are keys in mydict2
        if (key1 in mydict2) and (key2 in mydict2):
            
            # Calculate the difference: The elements of the values (lists) 
            # of mydict2 are strings, not numbers: What do you mean by 
            # 'difference'?
            difference = [(float(mydict2[key1]) - float(mydict2[key2][i]))
                          for i in range(len(mydict2[key1]))]

            print(value, key1, key2, difference)

Some things are a bit odd:

• Why are the values of mydict1 lists that contain only one string if you're actually interested in the string (it's not a problem, just a bit odd)?

• What is the "difference"? The elements in the values of mydict2 (lists) are strings, not numbers?

EDIT : Okay, for that kind of "difference" I'd try:

    ....
        
        # Check if both keys are keys in mydict2
        if (key1 in mydict2) and (key2 in mydict2):
            
            # Select all values from mydict2[key1] that are not in
            # mydict2[key2]
            difference = set(mydict2[key1]).difference(set(mydict2[key2]))
            
            print(value, key1, key2, difference)

Or use a list comprehension:

    ....
        
        # Check if both keys are keys in mydict2
        if (key1 in mydict2) and (key2 in mydict2):
            
            # Select all values from mydict2[key1] that are not in
            # mydict2[key2]
            difference = [value
                          for value in mydict2[key1] 
                          if value not in mydict2[key2]]
            
            print(value, key1, key2, difference)