Python 将字典中的负值更改为正值

Question

this have any way to check if i have negtive values (only integers) in my dictionary? And if yes to change all the negative values to positive values? For example:

D = {'Milk': -5, 'eggs': 144, 'flour': -10, 'chocolate': -2, 'yeast': 5, 'Cornflower': 3}

And i want to get:

D = {'Milk': 5, 'eggs': 144, 'flour': 10, 'chocolate': 2, 'yeast': 5, 'Cornflower': 3}

Answer 1

Iterate through the dictionary then use the abs() built-in function:

D = {'Milk': -5, 'eggs': 144, 'flour': -10, 'chocolate': -2, 'yeast': 5, 'Cornflower': 3}
for key, value in D.items():
   D[key] = abs(value)
print(D)

Output:

{'yeast': 5, 'Milk': 5, 'flour': 10, 'chocolate': 2, 'eggs': 144, 'Cornflower': 3}

If you want to do something else when the value is negative, use an if statement:

D = {'Milk': -5, 'eggs': 144, 'flour': -10, 'chocolate': -2, 'yeast': 5, 'Cornflower': 3}
for key, value in D.items():
   if value < 0:
       print('{} is negative'.format(key))
       D[key] = abs(value)
print(D)

Output:

chocolate is negative
Milk is negative
flour is negative
{'chocolate': 2, 'Cornflower': 3, 'Milk': 5, 'flour': 10, 'yeast': 5, 'eggs': 144}

Answer 2

Just use abs() to change the values to absolute values:

>>> {k: abs(v) for k, v in D.items()}
{'Milk': 5, 'eggs': 144, 'flour': 10, 'chocolate': 2, 'yeast': 5, 'Cornflower': 3}