Top Python Functions Used in Data Science

Most Commonly Used Python Functions in the Field of Data Science

Data analytics and visualization are some of the most important components of the Data Science technology stage nowadays. At present time, some libraries are there that make data analysis and visualization easier. Here are the most popular data analysis and visualization libraries in Python:

Exploring Datasets

The exploration of the data is essential in the course of data analysis. Panda's library features reading and write operations for CSV, Excel and SQL databases, which is important mostly for the use with tabular data. NumPy in PUthon gives facilities to index, slice and change the shape of arrays. This Pandas library of Python serves as a powerhouse for working with data by various ways, say filtering, grouping and summing up.

Data Cleaning And Preprocessing

Data cleaning and preprocessing is an essential instrument of data analysis, and Python's library have tools to remove dups, handle missing value and transform data to fit desired needs. This entails data functionality that is capable doing things like restructuring, reshaping, and merging of data among others.
Data Wrangling And Manipulation
The first step in any data analysis is to organize and manipulate the data. Python's NumPy library allows you to work with arrays by indexing them, slicing them, or reshaping them. It also allows you to perform mathematical operations on them, such as adding, subtracting, multiplying, and dividing. Pandas, on the other hand, provides you with tools for manipulating data, such as picking, sorting, and combining it.
Generating Statistical Reports
In Python, the SciPy library provides statistical analysis tools like hypothesis testing, regression and cluster analysis. In Python's Matplotlib library, data visualization tools like line charts, scatter charts, bar chart and histogram are available. Matplotlib can be used to create high-quality visualizations of scientific publications and reports.

Graphical Representations

Graphique symbols are key factors in data visualization. Along with Seaborn, the Python landscape has statistical graphics like heatmaps, pair plots, and facet grids. Therefore, this library is most effective as visualization becomes more complex, with several variables. Another powerful feature of the Python library Plotly is the capability to develop interactive plots which include scatter plots, line plots, and bar charts. By Plotly, you can make web based visualizations that you would promote to other people.

Python, specifically, is distinguished for its adaptability and serves as the most popular language utilized for data science. Python is a high-level programming language, easy to use as well as object-oriented in nature with an enormous set of libraries ideal for a lot of applications. Python is one of the programming languages and its developers already created lots of functions and types that are available to users.A built-in function is a pre-defined function that allows you to use the basic properties of a string or number in your rules. In the article, we have listed the top Python functions used in data science.

import pandas as pd

This simple import statement introduces us to the Pandas library. Pandas is the foundation of data handling and analysis. By naming Pandas as Python, we get access to many tools and functions that make data manipulation and analysis easier. The journey starts with one line of code: import pandas as pd. It is one of the top Python functions used in data science

len

The len() function takes a string value, a list value, a dataframe value, or any other Python object value and returns the length. This function is used in most IPython notebooks because data scientists often check the length of the data that they are transforming. According to the statistics, 38% of the notebooks use the len() function. Let's see an example below: We have used len() to check for a non-empty value from a list. Then, we have used len() again to print summaries of the output list. It is one of the top Python functions used in data science.
# Get all index values with non-empty reviews
non_zero_idx = [
ii for ii, review in enumerate(reviews_ints) if len(review) != 0]

# Print the number of non-empty reviews
print(len(non_zero_idx))

head()

The first time you see your data, your first reaction is one of curiosity. With the help of the head() function, you can get a glimpse into the first lines of your DataFrame. This way, you can quickly understand the structure and contents of your data.

For example,
print(data.head())

range

range is a function that generates a sequence of numbers. It takes the following inputs: Start, Stop, and Step with default value of Start as 0, Stop as the final value of range and Step as the increment value. Range() is normally used in a for() loop, hence it comes in third place at 36%Here is an example of how Range() can be used in a For loop:
# Return a list of batch size pairs
def get_batches(x, y, batch_size=100):
n_batches = len(x)//batch_size
x, y = x[:n_batches*batch_size], y[:n_batches*batch_size]

for ii in range(0, len(x), batch_size):
yield x[ii:ii+batch_size], y[ii:ii+batch_size]
StackOverflow's Most Common Questions

Str

str() is a function that converts input into strings. It is used by 14% of notebook users and is used 25 times on average. The following example shows how str() can be used to convert a set of data into strings to include filenames in publications.
for row, item in publications.iterrows():
md_filename = str(item.pub_date) + "-" + item.url_slug + ".md"
html_filename = str(item.pub_date) + "-" + item.url_slug
year = item.pub_date[:4]
describe()
As a data analyst, you need to understand the statistics of your data. With the describe() function, you can get summary statistics such as the mean, standard deviation and percentiles of the number columns of your DataFrame.

groupby()

The function groupby() is used to group data into one or more groups. This allows you to understand the unique features of different groups in your dataset. It also sets the scene for aggregation and detailed analysis of the data within the defined groups.

Example:

grouped_data = data.groupby('Category')

format

The format function allows you to dynamically print strings. Check out the examples below or check out the "The Most Python" report.

Example:
import numpy as np
x, y = np.full(4, 1.0), np.full(4, 2.0)
print("{} + {} = {}").format(x, y, x + y)
print(data.describe())

np.array

The Numpy array function returns an n-dimensional N-dimensional array based on the input. Numpy arrays can be used in machine learning because they store data much smaller and can be processed much faster than Python data objects (i).

_init__

The __init__ method is used to initialize the data in a Python object when a class is declared. When we declare a class, we initialize the data in the class. Then, we can use methods (also called functions) to change the data in the Python object.
The following is an example of how we can use the __init__ method in a Python class
# Sample class with init method
class Person:

# init method or constructor
def __init__(self, name):
self.name = name

# user-defined method
def say_hello(self):
print('Hello, my name is', self.name)

p = Person('Roger')
p.say_hello()

float

float() is a method that converts a string or an integer number to a floating point number. It is used in about 9.5 percent of notebooks and on average is called 19 times in each notebook.
# user-defined method
def say_hello(self):
print('Hello, my name is', self.name)

p = Person('Roger')
p.say_hello()

np.zeros

np.zeros generate a Numpy Zero array. This is useful for vector generation in Tensorflow or other machine learning algorithms.

pivot_table()

Use pivot_table() to transform and summarize your data. This function allows you to make pivot tables, which are powerful tools for transforming and aggregating data.

Example:
pivot_data = pd.pivot_table(data, index='Date', columns='Category', values='Value',

fillna()

Data integrity is very important. Fillna() takes care of missing values and replaces them with the values you have specified or calculated, like the average or median value.

Example:

data['Value'].fillna(data['Value'].mean(), inplace=True)

apply()

Sometimes your data needs a special treatment. Apply() allows you to apply special functions to the columns or rows of your DataFrame. This gives you the freedom to customize your data according to your needs.

Example:

def custom_function(x): return x * 2 data['Doubled_Value'] = data['Value'].apply
plot()
Using the plot() function, you can create an array of data visualizations, such as line plots, bar charts, and scatter plots. Data visualization is a powerful way to communicate and understand data. To use the plot() function in Matplotlib, you can import the program plt data.pyplot as follows:

Example:

import matplotlib.pyplot as plt data.plot(x='Date', y='Value', kind='line') plt.

merge()

The merge() function is useful for data analysts who need to combine data from multiple sources. This function allows you to merge two or more DataFacts based on a single column or index.

Example:

merged_data = pd.merge(data1, data2, on='common_column')
These top 10 Python functions used in data science tools. By using these functions, you can turn raw data into actionable insights.