How to format two dictionaries based on common keys? - python

Two dictionaries d1 and d2, can contain same keys with same values, same keys with different values and different keys. Need to consider with similar keys in both d1 and d2. If value of such similar keys of d1 lesser than d2, then capture such key:value pair.
And also, another to capture having key:value of d1 without lesser value of common key in both d1 and d2. Similarly, without higher value of common key in both d1 and d2 for d2. Able to achieve this but I think I'm using many dictionaries to handle this. Any better way this can be implemented ? Any optimisation can be done ?
Code:
d1 = {"a": 5, "b": 6, "c": 7, "d": 8, "e": 9, "f": 2}
d2 = {"a": 6, "b": 4, "c": 8, "d": 5, "f": 2}
less_values_of_d1 = {}
without_lesser_values_of_a_key_of_d1 = {}
without_higher_values_of_a_key_of_d2 = {}
for i in d1:
if i in d2:
if d1[i] < d2[i]:
less_values_of_d1[i] = d1[i]
else:
without_lesser_values_of_a_key_of_d1[i] = d1[i]
without_higher_values_of_a_key_of_d2[i] = d2[i]
else:
without_lesser_values_of_a_key_of_d1[i] = d1[i]
print("d1:", d1)
print("d2:", d2)
print("less_values_of_d1:", less_values_of_d1)
print("without_lesser_values_of_a_key_of_d1:", without_lesser_values_of_a_key_of_d1)
print("without_higher_values_of_a_key_of_d2:", without_higher_values_of_a_key_of_d2)
Output:
d1: {'a': 5, 'b': 6, 'c': 7, 'd': 8, 'e': 9, 'f': 2}
d2: {'a': 6, 'b': 4, 'c': 8, 'd': 5, 'f': 2}
less_values_of_d1: {'a': 5, 'c': 7}
without_lesser_values_of_a_key_of_d1: {'b': 6, 'd': 8, 'e': 9, 'f': 2}
without_higher_values_of_a_key_of_d2: {'b': 4, 'd': 5, 'f': 2}

You could do some dictionary comprehension. Here is one example.
less_values_of_d1 = {k:d1[k] for k in set(d1.keys()).
intersection(set(d2.keys()))
if d1[k]<d2[k]}

Related

Python Find permutable list in a dict list

Given
listOfDict = [{'ref': 1, 'a': 1, 'b': 2, 'c': 3},
{'ref': 2, 'a': 4, 'b': 5, 'c': 6},
{'ref': 3, 'a': 7, 'b': 8, 'c': 9}]
Lets' consider a list of permutable integer
[7,8,9]=[7,9,8]=[8,7,9]=[8,9,7]=[9,7,8]=[9,8,7] # (3!)
Each of this list has a unique mapping ref, so how given for (8,7,9) can I get ref=3 ?
Also in real case I might until 10 (a,b,c,d,e,f,g,h,i,j)...
You can generate a dictionary that maps the values as frozenset to the value of ref:
listOfDict = [{'ref': 1, 'a': 1, 'b': 2, 'c': 3},
{'ref': 2, 'a': 4, 'b': 5, 'c': 6},
{'ref': 3, 'a': 7, 'b': 8, 'c': 9}]
keys = ['a', 'b', 'c']
out = {frozenset(d[k] for k in keys): d['ref'] for d in listOfDict}
# {frozenset({1, 2, 3}): 1,
# frozenset({4, 5, 6}): 2,
# frozenset({7, 8, 9}): 3}
example:
check = frozenset((8,7,9))
out[check]
# 3
but I don't know in advance the name of the other keys!
Then use this approach:
out = {}
for d in listOfDict:
d2 = d.copy() # this is to avoid modifying the original object
out[frozenset(d2.values())] = d2.pop('ref')
out
or as a comprehension:
out = dict(((d2:=d.copy()).pop('ref'), frozenset(d2.values()))[::-1]
for d in listOfDict)
Here is a commented solution to your problem. The idea is to compare the sorted list of the values in a, b, c etc with the sorted values in list_of_ints. The sorted values will be the same for all permutations of a given set of numbers.
def get_ref(list_of_ints):
# Loop through dictionaries in listOfDict.
for dictionary in listOfDict:
# Get list of values in each dictionary.
vals = [dictionary[key] for key in dictionary if key != "ref"]
if sorted(vals) == sorted(list_of_ints):
# If sorted values are equal to sorted list of ints, return ref.
return dictionary["ref"])
By the way, I believe it would be cleaner to structure this data as a dict of dicts in the following way:
dicts = {
1: {'a': 1, 'b': 2, 'c': 3},
2: {'a': 4, 'b': 5, 'c': 6},
3: {'a': 7, 'b': 8, 'c': 9}
}
The code would then be:
def get_ref(list_of_ints):
for ref, dictionary in dicts.items():
if sorted(dictionary.values()) == sorted(list_of_ints):
return ref
Assuming that all integers in the permutations are unique, the code can be simplified further using sets instead of sorted lists.
Since its a list of dict I can call each dict as it self by using for loop
and record the first number on ref
for i in listOfDict:
ref_num=i["ref"]
and to turn dictunary to list we simply use:
z=list(i.values())
then the last step is to find if its the same input list if so we print/return the ref number
if z[1:]==InputList:
return ref_num
and the code should be like this:
listOfDict = [
{"ref": 1,
"a": 1,
"b": 2,
"c": 3},
{"ref": 2,
"a": 4,
"b": 5,
"c": 6},
{"ref": 3,
"a": 7,
"b": 8,
"c": 9},]
def find_ref_Num(InputList):
for i in listOfDict:
ref_num=i["ref"]
z=list(i.values())
if z[1:]==InputList:
return ref_num
print ("your ref number is: "+str(find_ref_Num([7,8,9])))

How to merge and sum two dictionaries into a single one whilst removing keys that are not common

I want to merge two dictionaries into a single dictionary with only common keys between the two.
Here are the two dictionaries
{"a": 5, "b": 8, "d": 9, "z": 4}
{"a": 1, "b": 1, "d": 2, "e": 1}
The result that I want is:
{"a": 6, "b": 9, "d": 11}
Do you guys know any way to do this?
You can try this -
Idea is to find intersections of common keys within both of the dictionaries and sum them up from both
d1.keys() & d2.keys()
d1 = {"a": 5, "b": 8, "d": 9, "z": 4}
d2 = {"a": 1, "b": 1, "d": 2, "e": 1}
result = {key: d1[key] + d2[key] for key in d1.keys() & d2.keys()}
result
{'a': 6, 'd': 11, 'b': 9}
First you need to get common keys between two dicts:
Lets say you have two dicts d1 and d2
common_keys = list(set(d1.keys()).intersection(set(d2.keys())))
new_dict = {}
for key in common_keys:
new_dict[key] = d1[key] + d2[key]

Nesting dictionary algorithm

Suppose I have the following dictionary:
{'a': 0, 'b': 1, 'c': 2, 'c.1': 3, 'd': 4, 'd.1': 5, 'd.1.2': 6}
I wish to write an algorithm which outputs the following:
{
"a": 0,
"b": 1,
"c": {
"c": 2,
"c.1": 3
},
"d":{
"d": 4,
"d.1": {
"d.1": 5,
"d.1.2": 6
}
}
}
Note how the names are repeated inside the dictionary. And some have variable level of nesting (eg. "d").
I was wondering how you would go about doing this, or if there is a python library for this? I know you'd have to use recursion for something like this, but my recursion skills are quite poor. Any thoughts would be highly appreciated.
You can use a recursive function for this or just a loop. The tricky part is wrapping existing values into dictionaries if further child nodes have to be added below them.
def nested(d):
res = {}
for key, val in d.items():
t = res
# descend deeper into the nested dict
for x in [key[:i] for i, c in enumerate(key) if c == "."]:
if x in t and not isinstance(t[x], dict):
# wrap leaf value into another dict
t[x] = {x: t[x]}
t = t.setdefault(x, {})
# add actual key to nested dict
if key in t:
# already exists, go one level deeper
t[key][key] = val
else:
t[key] = val
return res
Your example:
d = {'a': 0, 'b': 1, 'c': 2, 'c.1': 3, 'd': 4, 'd.1': 5, 'd.1.2': 6}
print(nested(d))
# {'a': 0,
# 'b': 1,
# 'c': {'c': 2, 'c.1': 3},
# 'd': {'d': 4, 'd.1': {'d.1': 5, 'd.1.2': 6}}}
Nesting dictionary algorithm ...
how you would go about doing this,
sort the dictionary items
group the result by index 0 of the keys (first item in the tuples)
iterate over the groups
if there are is than one item in a group make a key for the group and add the group items as the values.
Slightly shorter recursion approach with collections.defaultdict:
from collections import defaultdict
data = {'a': 0, 'b': 1, 'c': 2, 'c.1': 3, 'd': 4, 'd.1': 5, 'd.1.2': 6}
def group(d, p = []):
_d, r = defaultdict(list), {}
for n, [a, *b], c in d:
_d[a].append((n, b, c))
for a, b in _d.items():
if (k:=[i for i in b if i[1]]):
r['.'.join(p+[a])] = {**{i[0]:i[-1] for i in b if not i[1]}, **group(k, p+[a])}
else:
r[b[0][0]] = b[0][-1]
return r
print(group([(a, a.split('.'), b) for a, b in data.items()]))
Output:
{'a': 0, 'b': 1, 'c': {'c': 2, 'c.1': 3}, 'd': {'d': 4, 'd.1': {'d.1': 5, 'd.1.2': 6}}}

How to take a linear combination of several dictionaries in Python?

Here's some code to take a linear combination of two dictionaries:
def linearcombination(a1,d1,a2,d2):
return {k:a1*d1.get(k,0)+a2*d2.get(k,0) for k in {**d1,**d2}.keys()}
choosy1={"a":1,"b":2,"c":3}
choosy2={"a":1,"d":1}
choosy=linearcombination(1,choosy1,10,choosy2)
choosy is:
{'a': 11, 'c': 3, 'd': 10, 'b': 2}
How can I generalise it to allow linear combinations of arbitrary numbers of dictionaries?
Solution using sum in a dict comprehension over a set of keys:
from itertools import chain
def linear_combination_of_dicts(dicts, weights):
return {
k: sum( w * d.get(k, 0) for d, w in zip(dicts, weights) )
for k in set(chain.from_iterable(dicts))
}
Example:
>>> dicts = [{'a': 1, 'b': 2, 'c': 3}, {'a': 1, 'd': 1}]
>>> weights = [1, 10]
>>> linear_combination_of_dicts(dicts, weights)
{'c': 3, 'd': 10, 'a': 11, 'b': 2}
Here's an approach with pandas to handle dict key alignment:
def lc(coeffs, dicts):
return (pd.concat(pd.Series(d).fillna(0)*a for a,d in zip(coeffs,dicts))
.sum(level=0)
.to_dict()
)
lc([1,10], [choosy1, choosy2])
# {'a': 11, 'b': 2, 'c': 3, 'd': 10}

Python set an item value based other items in a dictionary

A = {0:{a:1, b:7}, 1:{a:5,b:5}, 2:{a:4,b:6}}
I want to attach an item guess to each sub dictionary based on the value b accounting of all b's in each sub dictionary.
Saying, in Dictionary A:
0-b-7 percentage of b: 7/(7+5+6)
1-b-5 percentage of b: 5/(7+5+6)
2-b-6 percentage of b: 1 - 7/(7+5+6) - 5/(7+5+6)
The desired Dictionary should be like
A = {0:{a:1, b:7, 'guess': 7/(7+5+6)},
1:{a:5,b:5, 'guess': 5/(7+5+6)},
2:{a:4,b:6, 'guess': 1 - 7/(7+5+6) - 5/(7+5+6)}}
I don't know how to incorporate the other two b's for a specific subdictionary.
One approach is to precompute the sum of all bs and then use it to add a new key-value pair to your dictionary.
b_total = float(sum(A[k]['b'] for k in A))
for k in A:
A[k]['guess'] = A[k]['b'] / b_total
#{0: {'a': 1, 'b': 7, 'guess': 0.3888888888888889},
# 1: {'a': 5, 'b': 5, 'guess': 0.2777777777777778},
# 2: {'a': 4, 'b': 6, 'guess': 0.3333333333333333}}
A = {0:{"a":1, "b":7}, 1:{"a":5,"b":5}, 2:{"a":4,"b":6}}
char = "b"
denominator = 0
# =========================
# First Calculate the sum
# =========================
for key in A:
inner_map = A[key]
denominator += inner_map[char]
# ========================================
# Now insert the new key to the inner_map
# ========================================
for key in A:
inner_map = A[key]
inner_map["guess"] = inner_map[char]/denominator
print(A)
Output:
{0: {'a': 1, 'b': 7, 'guess': 0.3888888888888889}, 1: {'a': 5, 'b': 5, 'guess': 0.2777777777777778}, 2: {'a': 4, 'b': 6, 'guess': 0.3333333333333333}}
Try this:
def add_calc(my_dict):
total_guesses = sum(map(lambda x: my_dict.get(x).get('b'), my_dict))
for item in my_dict.itervalues():
item.update({'guess': 1.0 * item.get('b') / total_guesses})
return my_dict
d = add_calc(A)
{0: {'a': 1, 'b': 7, 'guess': 0.3888888888888889},
1: {'a': 5, 'b': 5, 'guess': 0.2777777777777778},
2: {'a': 4, 'b': 6, 'guess': 0.3333333333333333}}
I'm on Python 2 btw, you didn't specify version
You can use dictionary unpacking:
A = {0:{'a':1, 'b':7}, 1:{'a':5, 'b':5}, 2:{'a':4, 'b':6}}
results = {a:{**b, **{'guess':b['b']/float(sum(c['b'] for _, c in A.items()))}} for a, b in A.items()}
Output:
{0: {'guess': 0.3888888888888889, 'b': 7, 'a': 1}, 1: {'guess': 0.2777777777777778, 'b': 5, 'a': 5}, 2: {'guess': 0.3333333333333333, 'b': 6, 'a': 4}}

Categories