How to store key, value pair in dictionary from file? - python-3.x

I have an input.txt file like below format.
A = Xyz
B
Value:274:53:3
C = 1190
E
WQQQW
Value:554
A = UrR
B
Value:113:00:1
C = 34
E
WQQQW
Value:982
I'd like to store in a dictionary the data related with A, B and E in order to get:
d = {
'A': ['Xyz', 'UrR'],
'B': ['274:53:3', '113:00:1'],
'E': ['554', '982'],
}
I'm doing like below, not I only storing the key, value pair related with A since the values for A are in the same line.
d = {"A":[],"B":[],"E":[]}
for line in open('input.txt'):
lst_line = line.replace(":", "=", 1).split("=")
if ("A" or "B" or "E") in lst_line[0]:
k = lst_line[0].strip()
v = lst_line[1].replace("\n", "").strip()
d[k].append(v)
>>> d
{'A': ['Xyz', 'UrR'], 'B': [], 'E': []}
I'm stuck in how to store the values for B that is one line below after Value: and for E that is 2 lines below after Value:.

Every key seems to have a very specific logic which can be divided into independent if conditions. Below code reads value for respective key based on the condition mentioned in question.
d = {"A": [], "B": [], "E": []}
with open("input.txt") as file:
while True:
line = file.readline() # read next line
if not line:
break # break on end of file
lst_line = line.replace(":", "=", 1).split("=") # key from line
if "A" in lst_line[0]:
k = lst_line[0].strip()
v = lst_line[1].replace("\n", "").strip()
d[k].append(v)
if "B" in lst_line[0]:
k = lst_line[0].strip()
line = file.readline() # read next line for value i.e. if key is B value is on the next line (one line below)
lst_line = line.replace(":", "=", 1).split("=") # get value for B
v = lst_line[1].replace("\n", "").strip()
d[k].append(v)
if "E" in lst_line[0]:
k = lst_line[0].strip()
file.readline() # skip junk line
line = file.readline() # read next line for value i.e. for E value is two lines below.
lst_line = line.replace(":", "=", 1).split("=") # get value for E
v = lst_line[1].replace("\n", "").strip()
d[k].append(v)
print(d)
Output:
{'A': ['Xyz', 'UrR'], 'B': ['274:53:3', '113:00:1'], 'E': ['554', '982']}

Here is how you can use regex:
import re
with open('file.txt', 'r') as r:
r = r.read()
dct = {'A': re.findall('(?<=A \= ).*?(?= \n)',r),
'B': re.findall('\d\d\d:\d\d:\d',r),
'E': re.findall('(?<=Value:)\d\d\d(?!:)',r)}
print(dct)
Output:
{'A': ['Xyz', 'UrR'],
'B': ['274:53:3', '113:00:1'],
'E': ['554', '982']}

Related

The problem of using {}.fromkey(['k1','k2'],[]) and {'k1':[],'k2':[]}

list1 = [99,55]
dict1 = {'k1':[],'k2':[]}
for num in list1:
if num > 77:
dict1['k1'].append(num)
else:
dict1['k2'].append(num)
print(dict1)
{'k1':[99],'k2':[55]}
But when I replaced dict1 = {'k1':[],'k2':[]} to {}.fromkeys(['k1','k2'],[]) , the result became {'k1': [99, 55], 'k2': [99, 55]}
why this happens? I really have no idea.
This happens because you are passing the same list object to both keys. This is the same situation as when you create an alias for a variable:
a = []
b = a
a.append(55)
b.append(99)
print(b)
prints [55, 99] because it is the same list instance.
If you want to make it more concise from a list of keys to initialize with empty list, you can do this:
dict1 = {k: [] for k in ('k1', 'k2')}
This will create a new list instance for every key.
Alternatively, you can use defaultdict
from collections import defaultdict
list1 = [99,55]
dict1 = defaultdict(list)
for num in list1:
if num > 77:
dict1['k1'].append(num)
else:
dict1['k2'].append(num)
print(dict1)
Also works.
The fromKeys() can also be supplied with a mutable object as the default value.
if we append value in the original list, the append takes place in all the values of keys.
example:
list1 = ['a', 'b', 'c', 'd']
list2 = ['SALIO']
dict1 = dict.fromkeys(list1, list2)
print(dict1)
output:
{'a': ['SALIO'], 'b': ['SALIO'], 'c': ['SALIO'], 'd': ['SALIO']}
then you can use this:
list1 = ['k1', 'k2']
dict1 = {'k1':[],'k2':[]}
list2 =[99,55]
for num in list2:
if num > 77:
a = ['k1']
dict1 = dict.fromkeys(a, [num])
else:
b = ['k2']
dict2 = dict.fromkeys(b,[num] )
res = {**dict1, **dict2}
print(res)
output:
{'k1': [99], 'k2': [55]}
You can also use the python code to merge dict code:
this function:
def Merge(dict1, dict2):
return(dict2.update(dict1))
then:
print(Merge(dict1, dict2)) #This return None
print(dict2) # changes made in dict2

swap the keys and values in a dictionary by storing the user input in dic

First the input should be dic length consider 3. then the input to a dic is keys and values separated by spaces i,e
"A 1
B 2
C 1"
now dic={A:1, B:2, C:1}
At first the keys and values and should be swapped, and if there are same keys and there values should be merged in a list and assigned to the same key as shown below.(these program should work for any length of dictionary)
the output should be dicout={1:['A','C'], 2:B}.
Thank you.
Define:
from collections import defaultdict
def make_dict(s):
d = defaultdict(list)
xs = s.split(" ")
for k, v in zip(xs[1::2], xs[::2]):
d[k].append(v)
for k, v in d.items():
if len(v) == 1:
d[k] = v[0]
return dict(d)
Example usage:
>>> make_dict("A 1 B 2 C 1")
{'1': ['A', 'C'], '2': 'B'}

Get value that from another defaultdict and update the original dict

Basically, I am trying to extract the values from one dictionary and update the value in another dictionary. I have four lists as follows:
a = [1,1,2,3,4,5]
b = [0,3,0,5,6,0]
c = [2,3,4,5,6,5]
d = [20,30,40,50,60,70]
So I use a defaultdict to store key,value pairs for a,b like:
one = defaultdict(list)
for k, v in zip(a, b):
one[k].append(v)
two = defaultdict(list)
for k, v in zip(c, d):
two[k].append(v)
Essentially, b is linked to c so I am trying to extract the values in the two dictionary and then update
the values in the one dictionary
So in the end one would look like {1: 30, 3: 50, 4: 60}
This is my code:
three = defaultdict(list)
for k, v in one.items():
if v in two.keys():
newvalue = two[v].values()
three[k].append(newvalue)
But I am now getting an error at line if v in two.keys(): as unhashable type: 'list'. I'm so lost, all
I want to do is use the values from one dictionary and then use those values to find the keys (which are the values
from the other table) and then get those corressponding values.
You are creating a dictionary of list in the beginning:
one = defaultdict(list)
for k, v in zip(a, b):
one[k].append(v)
[output] : defaultdict(list, {1: [0, 3], 2: [0], 3: [5], 4: [6], 5: [0]})
two = defaultdict(list)
for k, v in zip(c, d):
two[k].append(v)
[output] : defaultdict(list, {2: [20], 3: [30], 4: [40], 5: [50, 70], 6: [60]})
Therefore when calling k,v in one.items(), you are getting a key and a list.
Simply switch to iterate through the list , and you should be good to go
three = defaultdict(list)
for k, v in one.items():
for value in v:
if value in two.keys():
newvalue = two[value]
three[k].append(newvalue)
However I'm getting this output :
defaultdict(list, {1: [[30]], 3: [[50, 70]], 4: [[60]]})
Which sounds reasonable to me, but it is not your expected one, can you please explain ?
Let's try know with dic comprehension
output = { k : two[v_2] for k,v in one.items() for v_2 in v}
[output] : {1: [30], 2: [], 3: [50, 70], 4: [60], 5: []}
Request to sum :
Of course, multiple ways of doing it , the quickest is again with dict_comprehension and sum
output_sum = {k: sum(v) for k,v in output.items()}

return dictionary of file names as keys and word lists with words unique to file as values

I am trying to write a function to extract only words unique to each key and list them in a dictionary output like {"key1": "unique words", "key2": "unique words", ... }. I start out with a dictionary. To test with I created a simple dictionary:
d = {1:["one", "two", "three"], 2:["two", "four",
"five"], 3:["one","four", "six"]}
My output should be:
{1:"three",
2:"five",
3:"six"}
I am thinking maybe split in to separate lists
def return_unique(dct):
Klist = list(dct.keys())
Vlist = list(dct.values())
aList = []
for i in range(len(Vlist)):
for j in Vlist[i]:
if
What I'm stuck on is how do I tell Python to do this: if Vlist[i][j] is not in the rest of Vlist then aList.append(Vlist[i][j]).
Thank you.
You can try something like this:
def return_unique(data):
all_values = []
for i in data.values(): # Get all values
all_values = all_values + i
unique_values = set([x for x in all_values if all_values.count(x) == 1]) # Values which are not duplicated
for key, value in data.items(): # For Python 3.x ( For Python 2.x -> data.iteritems())
for item in value: # Comparing values of two lists
for item1 in unique_values:
if item == item1:
data[key] = item
return data
d = {1:["one", "two", "three"], 2:["two", "four", "five"], 3:["one","four", "six"]}
print (return_unique(d))
result >> {1: 'three', 2: 'five', 3: 'six'}
Since a key may have more than one unique word associated with it, it makes sense for the values in the new dictionary to be a container type object to hold the unique words.
The set difference operator returns the difference between 2 sets:
>>> a = set([1, 2, 3])
>>> b = set([2, 4, 6])
>>> a - b
{1, 3}
We can use this to get the values unique to each key. Packaging these into a simple function yields:
def unique_words_dict(data):
res = {}
values = []
for k in data:
for g in data:
if g != k:
values += data[g]
res[k] = set(data[k]) - set(values)
values = []
return res
>>> d = {1:["one", "two", "three"],
2:["two", "four", "five"],
3:["one","four", "six"]}
>>> unique_words_dict(d)
{1: {'three'}, 2: {'five'}, 3: {'six'}}
If you only had to do this once, then you might be interested in the less efficeint but more consice dictionary comprehension:
>>> from functools import reduce
>>> {k: set(d[k]) - set(reduce(lambda a, b: a+b, [d[g] for g in d if g!=k], [])) for k in d}
{1: {'three'}, 2: {'five'}, 3: {'six'}}

creating a dict based on two python dicts

I have two python dicts:
payload = {"key1":{"a":"1"},"key2":{"b":"2","c":"3"}}
and
data = {"1":"John","2":"Jacob"}
I would like my output to be:
{"key1":{"a":"John"},"key2":{"b":"Jacob","c":""}}
Any method that I try correctly prints the values, but does not update the output dictionary.
You can do something like this using dict comprehension :
payload = {"key1":{"a":"1"},"key2":{"b":"2","c":"3"}}
data = {"1":"John","2":"Jacob"}
final = {k: {i:data[j] if j in data.keys() else "" for i, j in payload[k].items()} for k in payload}
print(final)
Output:
{'key2': {'b': 'Jacob', 'c': ''}, 'key1': {'a': 'John'}}
There is no single method for this I am aware of, but you can use:
for k, v in payload.viewitems():
payload[k] = {}
for kv, vv in v.viewitems():
payload[k][kv] = data.get(vv, "")
if you then inspect payload it has the contents you are after:
{'key2': {'c': '', 'b': 'Jacob'}, 'key1': {'a': 'John'}}

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