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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 Keyboard shortcuts
For help, ESC + h
Step1:  Different heading levels
With text and $\LaTeX$ support.
You can also get monospaced fonts by indenting 4 spaces
Step2:  SQL
SELECT first_name,
       last_name,
       year_of_birth
FROM presidents
WHERE year_of_birth &gt; 1800;
Step4:  Tab; shift-tab; shift-tab-tab; shift-tab-tab-tab-tab; and more!
Step5:  Multicursor magic
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Python Code:
# in select mode, shift j/k (to select multiple cells at once)
# split cell with ctrl shift -
# merge with shift M
first = 1
second = 2
third = 3
Explanation: Keyboard shortcuts
For help, ESC + h
End of explanation
import numpy as np
np.random.choice()
Explanation: Different heading levels
With text and $\LaTeX$ support.
You can also get monospaced fonts by indenting 4 spaces:
mkdir toc
cd toc
Wrap with triple-backticks and language:
bash
mkdir toc
cd toc
wget https://repo.continuum.io/miniconda/Miniconda3-latest-MacOSX-x86_64.sh
End of explanation
mylist = !ls 
[x.split('_')[-1] for x in mylist]
%%bash
pwd 
for i in *.ipynb
do
    echo $i | awk -F . '{print $1}'
done
echo
echo "break"
echo
for i in *.ipynb
do
    echo $i | awk -F - '{print $2}'
done
Explanation: SQL
SELECT first_name,
       last_name,
       year_of_birth
FROM presidents
WHERE year_of_birth &gt; 1800;
End of explanation
def silly_function(xval):
    Takes a value and returns the absolute value.
    xval_sq = xval ** 2.0
    1 + 4
    xval_abs = np.sqrt(xval_sq)
    return xval_abs
silly_function?
silly_function??
silly_function()
import numpy as np
# 
np.linspace??
# 
np.linspace?
ex_dict = {}
# Indent/dedent/comment
for _ in range(5):
    ex_dict["one"] = 1
    ex_dict["two"] = 2
    ex_dict["three"] = 3
    ex_dict["four"] = 4
ex_dict
Explanation: Tab; shift-tab; shift-tab-tab; shift-tab-tab-tab-tab; and more!
End of explanation
ex_dict["one_better_name"] = 1.
ex_dict["two_better_name"] = 2.  
ex_dict["three_better_name"] = 3.
ex_dict["four_better_name"] = 4.
Explanation: Multicursor magic
End of explanation
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