# Mean_standar deviation_variance calculator

kindly help, I have a syntax error in the project below.

``````import numpy as np
def calculate(list):

if len(list)!=9:
raise ValueError("List should have nine elements.")
list=np.array(list).reshape((3,3))

'mean':[(np.mean(list,axis=1)).tolist(), (np.mean(list,axis=0)).tolist(), np.mean(list)],

'variance':[(np.var(list,axis=1)).tolist(), (np.var(list,axis=0)).tolist(), np.var(list)],

'standard deviation':[(np.std(list,axis=1)).tolist(), (np.std(list,axis=0)).tolist(), np.std(list)],

'max':[(np.max(list,axis=1)).tolist(), (np.max(list,axis=0)).tolist(), np.max(list)],

'min':[(np.min(list,axis=1)).tolist(), (np.min(list,axis=0)).tolist(), np.min(list)],

'sum':[(np.sum(list,axis=1)).tolist(), (np.sum(list,axis=0)).tolist(), np.sum(list)]

return{
'mean': mean,
'variance': variance,
'standard deviation': std_dev,
'max': max,
'min': min,
'sum': sum
}
``````

Iâ€™ve edited your post for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.

You can also use the â€śpreformatted textâ€ť tool in the editor (`</>`) to add backticks around text.

See this post to find the backtick on your keyboard.
Note: Backticks (`) are not single quotes (â€™).

This looks like the definition of a dictionary object, but I donâ€™t see a preceding declaration.

I suppose you meant to put those variable names in place of the dictionary keys above.

Personally I would write this:

``````return {
'mean':[(np.mean(list,axis=1)).tolist(), (np.mean(list,axis=0)).tolist(), np.mean(list)],

'variance':[(np.var(list,axis=1)).tolist(), (np.var(list,axis=0)).tolist(), np.var(list)],

'standard deviation':[(np.std(list,axis=1)).tolist(), (np.std(list,axis=0)).tolist(), np.std(list)],

'max':[(np.max(list,axis=1)).tolist(), (np.max(list,axis=0)).tolist(), np.max(list)],

'min':[(np.min(list,axis=1)).tolist(), (np.min(list,axis=0)).tolist(), np.min(list)],

'sum':[(np.sum(list,axis=1)).tolist(), (np.sum(list,axis=0)).tolist(), np.sum(list)]
}
``````
1 Like

â€ślistâ€ť is a Python-keyword and should never be overwritten.

The error itself is prett simple, you didnâ€™t create an object, you just assigned a list to a nameless string containing â€śmeanâ€ť - that just cannot work.
Meaning you never declared a variable `mean` yet you assign it within the dictionairy.

Sh0es gave you the solution for this.

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