Whitespace in Python is too important to allow any other kind of comment besides the # comment that goes to the end of the line. Take this code:

x = 1
for i in range(10):
             x = x + 1
/* Print. */ print x

Because indentation determines scope, the parser has no good way of knowing the control flow. It can’t reasonably eliminate the comment and then execute the code after it. (It also makes the code less readable for humans.) So no inline comments.

This is pretty hideous, but you can take any text convert it into a string and then take then length of that string then multiply by zero, or turn it into any kind of invalid code.
example

history = model.fit_generator(train_generator,steps_per_epoch=8,epochs=15+0*len(", validation_data=validation_generator"), validation_steps=8,verbose=2)

No, there are no inline-block comments in Python.
But you can place your comment (inline) on the right.
That’s allows you to use syntax and comments on the same line.
Anyway, making comments to the left of your code turn reading difficult, so…

Ex:

x = 1 # My variable

If you’re doing something like a sed operation on code and really need to insert plain text without interfering with the rest of the line, you can try something like:

("This is my comment", some more code here...)[1]

Eg.,

my_variable = obsolete_thing + 100

could be transformed with sed -e 's/obsolete_thing/("replacement for &", 1345)[1]/' giving:

my_variable = ("replacement for obsolete_thing", 1234)[1] + 100

You can insert inline comment.
Like this

x=1; """ Comment """; x+=1; print(x);

And my python version is "3.6.9"

The octaves of a Piano are numbered and note frequencies known
(see wikipedia).
I wanted to inline comment the notes in a list of frequencies
while maintaining standard Human readable sequencing of notes.
Here is how I did it; showing a couple of octaves.

def A(octave, frequency):
    "Octave numbering for twelve-tone equal temperament"
    return frequency

NOTE=[
    155.5635 , 164.8138, 174.6141, 184.9972, 195.9977, 207.6523,
A(3,220.0000), 233.0819, 246.9417, 261.6256, 277.1826, 293.6648,
    311.1270 , 329.6276, 349.2282, 369.9944, 391.9954, 415.3047,
A(4,440.0000), 466.1638, 493.8833, 523.2511, 554.3653, 587.3295]

Of course, adjust setup.cfg and comment to satisfy pycodestyle,
pyflakes, and pylint.

I argue that maintaining columns and annotating A4 as A(4,440)
is superior to enforcing rigid style rules.

A function ignoring a formal argument is run once
at list initialization.
This is not a significant cost.
Inline commenting is possible in python.
You just have to be willing to bend style rules.

I miss inline-comments mainly to temporarily comment out parameters in functions or elements in list/dicts. Like it is possible in other languages:

afunc(x, /*log=True*/, whatever=True)
alist = [1,2,3]

The only workaround, i guess, is to but them on separate lines like:

afunc(
    x,
    # log=True,
    whatever=True,
)

alist = [
   1,
   # 2,
   3,
]

However, as python is often used as rapid prototyping language and functions (due to no overloading) often have lots of optional parameters, this solution does not fell very "pythonic"…

Update

I meanwhile really like the "workaround" and changed my opinion about being not pythonic. Also, some formatters like Black will automatically arrange arguments or elements of an array/dict on seperate lines if you add a comment at the end. This is called Magic Trailing Comma