Removing keys in pair form from dictionary-CodePudding

Suppose I have a python dictionary, tDosDict, like

{('M1', 'P1'): 6.0,
 ('M1', 'P2'): 10.0,
 ('M1', 'P3'): 4.0,
 ('M2', 'P1'): 7.0,
 ('M2', 'P2'): 6.0,
 ('M2', 'P3'): 5.0}

I am making some operations say,

valMin = min(tDosDict.values())
jobsR = [key for key in tDosDict if tDosDict[key] == valMin]

So I find that jobsR as ('M1', 'P3'). Now I would like to remove the all the keys where 'P3' appears from the tDosDict. So my updated keys will be

{('M1', 'P1'): 6.0,
 ('M1', 'P2'): 10.0,
 ('M2', 'P1'): 7.0,
 ('M2', 'P2'): 6.0,}

Again I shall make the same operation to drop the keys. I tried it in the following way, but it is not working

for key, value in tDosDict.items():
    if jobsR[0][1] in key[1]:
        tDosDict.pop(jobsR[0][1], None)

Kindly help me. Also I have to push it in the loop to iterate the process.

CodePudding user response：

The issue is that you cannot edit an iterable while iterating over it. To get around this I made a list of the keys to remove, then removed them in a separate loop:

tDosDict = {('M1', 'P1'): 6.0,
 ('M1', 'P2'): 10.0,
 ('M1', 'P3'): 4.0,
 ('M2', 'P1'): 7.0,
 ('M2', 'P2'): 6.0,
 ('M2', 'P3'): 5.0}
 
valMin = min(tDosDict.values())
jobsR = [key for key in tDosDict if tDosDict[key] == valMin]

remove_list = []
for key, value in tDosDict.items():
    if jobsR[0][1] in key[1]:
        remove_list.append(key)
for item in remove_list:
    tDosDict.pop(item)
    
print(tDosDict)

Output:

{('M1', 'P1'): 6.0, ('M1', 'P2'): 10.0, ('M2', 'P1'): 7.0, ('M2', 'P2'): 6.0}

CodePudding user response：

An iteration like the following would achieve what you need - no need to iterate twice:

d = {('M1', 'P1'): 6.0, ('M1', 'P2'): 10.0, ('M1', 'P3'): 4.0, ('M2', 'P1'): 7.0, ('M2', 'P2'): 6.0, ('M2', 'P3'): 5.0}

{x: y for x, y in d.items() if x[0] in ["M1", "M2"] and x[1] != "P3"}

OUTPUT

{('M1', 'P1'): 6.0, ('M1', 'P2'): 10.0, ('M2', 'P1'): 7.0, ('M2', 'P2'): 6.0}

CodePudding user response：

Don't remove from dict but directly create new dict with elements which you want to keep.

Use != instead of ==

tDosDict = {key:val for key, val in tDosDict.items() if val != valMin}

tDosDict = {
    ('M1', 'P1'): 6.0,
    ('M1', 'P2'): 10.0,
    ('M1', 'P3'): 4.0,
    ('M2', 'P1'): 7.0,
    ('M2', 'P2'): 6.0,
    ('M2', 'P3'): 5.0
}

valMin = min(tDosDict.values())
#jobsR = [key for key in tDosDict if tDosDict[key] == valMin]

tDosDict = {key:val for key, val in tDosDict.items() if val != valMin}

print(tDosDict)

CodePudding user response：

This will also give desired out put d={('M1', 'P1'): 6.0, ('M1', 'P2'): 10.0, ('M1', 'P3'): 4.0, ('M2', 'P1'): 7.0, ('M2', 'P2'): 6.0, ('M2', 'P3'): 5.0}

valMin = min(d.values()) jobsR = [key for key in d if d[key] == valMin]

for key in [key for key in d if key[1] ==jobsR[0][1] ]: del d[key]

print(d)