# Cool.py
Make Python code cooler. 100% coverage. Use and enjoy this code!
## Install
```
pip install cool
```
Or fetch from github
```
pip install git+https://github.com/abersheeran/cool@setup.py
```
## Usage
### Pipe
*Note: as fast as you didn't use F!*
Use pipeline to pass data as a positional parameter to the next function.
```python
from cool import F
assert range(10) | F(filter, lambda x: x % 2) | F(sum) == 25
```
Or you need to pass multiple parameters through the pipeline. Note that `FF` can only accept one parameter, and it must be an iterable object.
```python
from cool import FF
assert (1, 2) | FF(lambda x, y: x + y) == 3
```
You can use `...` as a placeholder. This is useful when you need to pass non-continuous parameters to create a partial function.
```python
from functools import reduce
from cool import F
assert range(10) | F(reduce, lambda x, y: x + y) == 45
assert range(10) | F(reduce, lambda x, y: x + y, ..., 10) == 55
square = F(pow, ..., 2)
assert range(10) | F(map, square) | F(sum) == 285
```
The `range(10) | F(reduce, lambda x, y: x + y, ..., 10)` is equivalent to `reduce(lambda x, y: x + y, range(10), 10)`.
### Redirect
Just like the redirection symbol in `Shell`, you can redirect the output to a specified file or `TextIO` object through `>` or `>>`.
*Note: `R` inherits from `functools.partial`.*
```python
from pathlib import PurePath
from cool import R
# Redirect output to specified filepath
R(print, "hello") > PurePath("your-filepath")
# Append mode
R(print, "world") >> PurePath("your-filepath")
```
Redirect to opened file or other streams.
```python
from io import StringIO
from cool import R
with open("filepath", "a+", encoding="utf8") as file:
R(print, "hello") >> file
out = StringIO("")
R(print, "hello") > out
out.seek(0, 0)
assert out.read() == "hello\n"
```
Maybe you also want to block the output, just like `> /dev/null`.
```python
from cool import R
R(print, "hello") > None
# Or
R(print, "hello") >> None
```
Note that after the calculation is over, `R` will faithfully return the return value of your function. Try the following example.
```python
from pathlib import PurePath
from cool import F, R
def func(num):
return range(num) | F(map, lambda x: print(x) or x) | F(sum)
print(R(func, 10) > PurePath("filepath"))
```
### Set Global
Maybe you don't want to use `from cool import F` in every file of the entire project, you can use the following code to set it as a global function, just like `min`/`max`/`sum`.
```python
import cool
cool.set_global(cool.F, cool.FF)
```
Maybe you also want to expose `functools.reduce` to the world, just like `map`/`filter`.
```python
import functools
import cool
cool.set_global(cool.F, cool.FF, functools.reduce)
```
