From most frequent words how to extract technical skill words
From what I understand, you need more than 1-word terms. Thus, it's better to go for n-grams.

Start with creating n-grams

import re
from nltk.util import ngrams

s = s.lower()
s = re.sub(r'[^a-zA-Z0-9\s]', ' ', s)
tokens = [token for token in s.split(" ") if token != ""]
output = list(ngrams(tokens, 2))


You should get 1-gram, 2-grams and 3-grams at least to cover all possible terms.

Then you can use a Computer Science Ontology (CSO) which includes about 14k technical terms.

An alternative would be to use their own Classifier that gets a text as input and annotate terms on it from the same ontology. You can find a demo here https://cso.kmi.open.ac.uk/classify/

When I try to classify the abstract of Machine Learning from the Wikipedia article, I get the following results


  Machine learning (ML) is the scientific study of algorithms and
  statistical models that computer systems use to effectively perform a
  specific task without using explicit instructions, relying on patterns
  and inference instead. It is seen as a subset of artificial
  intelligence. Machine learning algorithms build a mathematical model
  based on sample data, known as "training data", in order to make
  predictions or decisions without being explicitly programmed to
  perform the task.1:2 Machine learning algorithms are used in a
  wide variety of applications, such as email filtering, and computer
  vision, where it is infeasible to develop an algorithm of specific
  instructions for performing the task. Machine learning is closely
  related to computational statistics, which focuses on making
  predictions using computers. The study of mathematical optimization
  delivers methods, theory and application domains to the field of
  machine learning. Data mining is a field of study within machine
  learning, and focuses on exploratory data analysis through
  unsupervised learning.[3][4] In its application across business
  problems, machine learning is also referred to as predictive
  analytics.



artificial intelligence 
computer systems 
computer vision 
correlation
analysis 
data mining 
email 
inference 
machine learning 
optimization
unsupervised learning