Snakes

The most logical explanation could be that she is beginning a shed. Many snakes go off food for that time. If that is the case, there are no real concerns and all should reestablish on its normal pattern when she is finished. She should have the appropriate humidity to properly do this with ease.
Check her hydration. Give her a good soak in the tub massaging her middle toward the vent.
If she were bred anytime this season, she could be pregnant. Weights should be accurately measured every other week to ensure she is not losing much if any weight.
Parasites could be the issue. This is more likely if you feed live or f/kzperiodz Frozen feeders are said to be parasite free concerning the temps they are kept in. A fecal test will answer that question.
If it is male, it could be simply because he would like to hibernate if it is near winter or winter where you are. If it is female, it can still be because they want to hibernate but its most likely males are the one that would like to hibernate most.
Also, snakes do not always eat weekly. They may go off food at times. If your fecal check comes back clear, keep offering, she will eat when ready.

I know that my Ball Pythons and my Burmese Python can go around a year without eating and still be okay. Don't worry too much about her not wanting to eat at the moment. If she goes around a month and seems to not want to feed, I would call the local vet and see if they can just do a quick check for you. My Balls don't really want to eat during the months of November-Feburary. They are great eaters otherwise. They get to were they sleep most of the time during those months and I get them out weekly to check on them. My Burmese will eat any time you put food in with him. I hope this helped you a little bit.

General information!

Anacondas Scientific classification.

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Class: Reptilia

Order: Squamata

Suborder: Serpentes

Family: Boidae

Subfamily: Boinae

Genus: Eunectes

The question what is the biggest snake can be confusing, the biggest as far as girth (largest being measured at 44 inches or 1,1176 m) is the Green Anaconda, on average anacondas are more then 20 ft (6.09 m) long many reaching lengths of 29ft ( 8.83 m) or more, with a weight of over 550 lbs ( 249.48 kg), in terms of length then and only then will the Reticulated Python exceed the anaconda, the longest python was measured at 33 ft ( 10.05 m) but even this python can't match the total mass of the anaconda.

Anacondas are members of the Boidae family of reptiles and spend most of their time in rivers and swamps of the Amazon in South America which makes them excellent swimmers and are capable of holding their breath for around 15 minutes, female anacondas are generally larger then the males and bear their young live and are called "Neonates", the number of young varies, some have produced 100 babies, but the average is between 20 to 40 babies. Diet consist of (depending on the size of the anaconda, the larger the snake the larger the prey) large/small rodents like capybaras, also pigs, caiman, jaguars, deer, dogs, birds even fish and is acquired by ambushing with a quick strike, 100 rear-facing sharp teeth hold the prey while suffocating it with constriction, (the anaconda is so powerful it generally crushes it's prey) then swallowing it whole, the digestion of the anaconda is very slow thereby allowing it to survive without food for well over a year.

Anacondas have around a 30 year life span and the biggest threat to it is man and loss of their habitat.

A snake came to my water-trough

On a hot, hot day, and I in pyjamas for the heat,

To drink there.

In the deep, strange-scented shade of the great dark carob-tree

I came down the steps with my pitcher

And must wait, must stand and wait, for there he was at the trough before

me.

He reached down from a fissure in the earth-wall in the gloom

And trailed his yellow-brown slackness soft-bellied down, over the edge of

the stone trough

And rested his throat upon the stone bottom,

i o And where the water had dripped from the tap, in a small clearness,

He sipped with his straight mouth,

Softly drank through his straight gums, into his slack long body,

Silently.

Someone was before me at my water-trough,

And I, like a second comer, waiting.

He lifted his head from his drinking, as cattle do,

And looked at me vaguely, as drinking cattle do,

And flickered his two-forked tongue from his lips, and mused a moment,

And stooped and drank a little more,

Being earth-brown, earth-golden from the burning bowels of the earth

On the day of Sicilian July, with Etna smoking.

The voice of my education said to me

He must be killed,

For in Sicily the black, black snakes are innocent, the gold are venomous.

And voices in me said, If you were a man

You would take a stick and break him now, and finish him off.

But must I confess how I liked him,

How glad I was he had come like a guest in quiet, to drink at my water-trough

And depart peaceful, pacified, and thankless,

Into the burning bowels of this earth?

Was it cowardice, that I dared not kill him? Was it perversity, that I longed to talk to him? Was it humility, to feel so honoured?

I felt so honoured.

And yet those voices:

If you were not afraid, you would kill him!

And truly I was afraid, I was most afraid, But even so, honoured still more

That he should seek my hospitality

From out the dark door of the secret earth.

He drank enough

And lifted his head, dreamily, as one who has drunken,

And flickered his tongue like a forked night on the air, so black,

Seeming to lick his lips,

And looked around like a god, unseeing, into the air,

And slowly turned his head,

And slowly, very slowly, as if thrice adream,

Proceeded to draw his slow length curving round

And climb again the broken bank of my wall-face.

And as he put his head into that dreadful hole,

And as he slowly drew up, snake-easing his shoulders, and entered farther,

A sort of horror, a sort of protest against his withdrawing into that horrid black hole,

Deliberately going into the blackness, and slowly drawing himself after,

Overcame me now his back was turned.

I looked round, I put down my pitcher,

I picked up a clumsy log

And threw it at the water-trough with a clatter.

I think it did not hit him,

But suddenly that part of him that was left behind convulsed in undignified haste.

Writhed like lightning, and was gone

Into the black hole, the earth-lipped fissure in the wall-front,

At which, in the intense still noon, I stared with fascination.

And immediately I regretted it.

I thought how paltry, how vulgar, what a mean act!

I despised myself and the voices of my accursed human education.

And I thought of the albatross

And I wished he would come back, my snake.

For he seemed to me again like a king,

Like a king in exile, uncrowned in the underworld,

Now due to be crowned again.

And so, I missed my chance with one of the lords

Of life.

And I have something to expiate:

A pettiness.