Adding "sequential" information to python list using dictionaries

The problem

I would like to create a dictionary of dicts out of a flat list I have in order to add a "sequentiality" piece of information, but I am having some trouble finding a solution.

The list is something like

a = ['Q=123', 'W=456', 'E=789', 'Q=753', 'W=159', 'E=888']

and I am shooting for a dict like:

dictionary = {
    'Step_1': {
        'Q=123', 
        'W=456', 
        'E=789'
    },
    'Step_2': {
        'Q=753', 
        'W=159', 
        'E=888'
    }
}

I would like to end up with a function with an arbitrary number of Steps, in order to apply it to my dataset. Suppose that in the dataset there are lists like a with 1 <= n <6 Steps each.

My idea

Up to now, I came up with this:

nsteps = a.count("Q")
data = {}
for i in range(nsteps):
    stepi = {}
    for element in a:
            new = element.split("=")
            if new[0] not in stepi:
                stepi[new[0]] = new[1]
            else:
                pass
    data[f"Step_{i}"] = stepi

but it doesn’t work as intended: both steps in the final dictionary contain the data of Step_1.
Any idea on how to solve this?

>Solution :

One way would be:

a = ['Q=123', 'W=456', 'E=789', 'Q=753', 'W=159', 'E=888']

indices = [i for i, v in enumerate(a) if 'Q' in v]

dictionary = {f'Step_{idx+1}': {k: v for k, v in [el.split('=') for el in a[s:e]]} 
              for idx, (s, e) in enumerate(zip(indices, indices[1:] + [len(a)]))}

print(dictionary)

{'Step_1': {'Q': '123', 'W': '456', 'E': '789'}, 
'Step_2': {'Q': '753', 'W': '159', 'E': '888'}}