Is "in the bag" an idiom?
breakdown

Putting it in a bag means putting it in your pocket, which means getting something. Sac, refers to the pocket.

Idiom in the bag: knock out from the bag, leak out from the bag, leak out from the bag, take something from the bag, taper it from the bag and fill it.

2. Capsule name

Nanman

(1) (sound and sound. The word is subordinate to the item, and the item is also pronounced. "Fragrant" means "wrapped" and "containing (foreign matter)". A pocket with something in it. Note: the original meaning of "bag" does not refer to empty bag, but the extended meaning can refer to empty bag. )

(2) with the original meaning [package; Pocket]

So are capsules. -Xu Shen's Shuowen in the Eastern Han Dynasty

Close the capsule. -Ikun. Sparse: "So store things."

Confined in a space capsule. -Poetry, elegance and Gong Liu. Chuan: "Small is big."

It has nothing but a tunic. -"Han Shu Wang Jichuan". Note: "There is a bottom called a purse, but there is no bottom."

The medicine bag was lifted. -"The Warring States Policy Yance"

As Mr. Wang pointed out, the wolf is in the bag. -Ma "The Legend of Zhongshan Wolf"

Put it in the schoolbag —— Liu Yichuan by Don Lee Wei Chao.

The cone is in the bag. -Historical Records, Biography of Ping Yuanjun and Jade Qing

Fill it with tips. -Song Ouyang Xiu's "Introduction to Lingguan Biography"

(3) Another example: a bag (pocket; Representative property); Empty pockets (no money in pockets); A pocket full of money; The bag is bleak (there is no money in the pocket); Capsule cone reveals glume shell (metaphor reveals talent); Capsule surgery (referring to ingenuity); Bags (luggage); Capsule bottom (inside the bag); Empty bag (no money in the bag); Burst (penniless); Schoolbag (schoolbag)

(4) Something resembling a pocket [anything bag-shaped]. Such as: gallbladder; Renal capsule; Cystic contraction (scrotal contraction)

Capsule [movement]

Nanman

bagging

Donkey, schoolbag. -Ma "The Legend of Zhongshan Wolf"

(2) Once again

Try again.

(3) Another example: rice in the bag (rice in the pocket); Pack the piano (put the piano in the bag); Capsule loading (packed in bags and transported away); Burst (put a person in a bag and kill him); Bagged soil (bagged soil)

(4) coverage; Cover [cover]

Cover your mouth with a cloth. -Liu Tang Zongyuan's Children's Biography

5. Another example: capsule swallowing (including nibbling); The head of the capsule (covered with a bag); Capsule beating (sealing, sealing); Covering the four seas (unifying the whole country; All-encompassing)