item

1. When you want to use a character string as a code (assignment statement) `eval`
2. When you want to overlap two with hist and make one transparent `.hist (alpha = 0.5)`
3. I want to use the square root! ``math.sqrt (x)``
4. I want to make a list that numpy can use as it is! `` `np.array ([0, 1, 2])` `
5. etc...

1. When you want to use a character string as a code (assignment statement) `eval`

A so-called assignment statement that can use the character string inside as a code with `eval ("~~~ ")`?

`python`

``````
list = ["dog","cat"]
dog, cat = "wan", "nya"
for i in list:
print(eval(i))

# wan
# nya
``````

2. When you want to overlap two with hist and make one transparent `.hist (alpha = 0.5)`

`.hist (alpha =?)` Makes it transparent, `1 ~ 0` makes it darker as it gets closer to` 1`, and `0.0` makes it completely transparent.

`python`

``````
x = np.random.randn(10000)
plt.hist(x, alpha =0.5)
plt.hist(x - 2, alpha = 0.5)
plt.show
``````

3. I want to use the square root! `math.sqrt (x)`

I want to use the square root easily! In such a case, use `math` to`.sqrt (x)`!

`python`

``````
import math
print(math.sqrt(4))
print(math.sqrt(144))

# 2.0
# 12.0
``````

4. I want to make a list that numpy can use as it is! `Np.array ([0, 1, 2])`

By creating a list with `np.array ([list of int])`, you can apply the numpy module to the list as it is.

`python`

``````
x = np.array([812, 973, 1001])
np.max(x)

# 1001
``````

5.etc...