Comparison of Python and R: The Magic of Syntactic Sugar

My perspective on development has broadened since I began to appreciate the elegance of Python and R. Data science is a multifaceted discipline that can be tackled in various ways. However, it demands a delicate balance of language proficiency, library knowledge, and domain expertise. The extensive capabilities of Python and R provide us with what we call “syntactic sugar”: syntax that simplifies our work and enables us to solve intricate problems with concise and sophisticated solutions.

These languages equip us with distinct approaches to exploring solutions. Each has its own advantages and disadvantages. The key to utilizing them effectively lies in understanding which problem types are best suited to each tool and determining the most effective way to present our findings. The syntactic sugar in each language contributes to increased efficiency in our workflow.

R and Python act as interactive layers on top of lower-level code, empowering data scientists to use their preferred language for data exploration, visualization, and modeling. This interactivity frees us from the tedious cycle of code editing and compilation, simplifying our tasks significantly.

These high-level languages allow us to work with minimal obstacles and achieve more with less code. The syntactic sugar of each language facilitates rapid testing of ideas within a REPL (read-evaluate-print loop), an interactive environment for real-time code execution. This iterative approach is a crucial element in the modern data process cycle.

R vs. Python: Expressive and Specialized

The strength of R and Python is rooted in their expressiveness and adaptability. Each language excels in specific use cases, outperforming the other. Furthermore, they approach problem-solving from different angles, producing distinct output types. Consequently, they attract distinct developer communities, each with their own language preference. As these communities organically expand, their favored languages and feature sets naturally evolve towards unique syntactic sugar styles that minimize the code required for problem-solving. And as a language and its community mature, its syntactic sugar tends to become even more refined.

While each language offers a robust toolkit for tackling data challenges, we must approach these problems strategically, exploiting the specific strengths of each tool. R, conceived as a statistical computing language, boasts an extensive array of tools designed for statistical analysis and data interpretation. Python, with its machine learning capabilities, addresses similar problems but primarily those suitable for machine learning models. Consider statistical computing and machine learning as two distinct schools of thought within data modeling: Although interconnected, their origins and data modeling paradigms differ.

R Excels in Statistics

R has blossomed into a comprehensive platform for statistical analysis, linear modeling, and visualization. Its packages, deeply rooted in the R ecosystem for decades, are mature, efficient, and well-documented. When a problem demands a statistical computing approach, R is the optimal choice.

The adoration for R within its community stems from these key factors:

  • Powerful methods for discrete data manipulation, computation, and filtering.
  • Flexible chaining operators for seamlessly connecting these methods.
  • Concise syntactic sugar that empowers developers to solve complex problems using familiar statistical and visualization techniques.

A Simple Linear Model With R

To illustrate R’s conciseness, let’s craft an example that predicts diamond prices. We’ll use the diamonds default dataset, pre-installed with R, containing attributes like color and cut.

We’ll also showcase R’s pipe operator (%>%), akin to the Unix command-line pipe (|) operator. This beloved element of R’s syntactic sugar, provided by the tidyverse package suite package, revolutionizes R coding. This operator and its resulting code style are game-changers because they enable the chaining of R verbs (i.e., R functions) to break down and solve a wide range of problems.

The following code snippet loads the necessary libraries, prepares our data, and generates a linear model:

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library(tidyverse)
library(ggplot2)

mode <- function(data) {
  freq <- unique(data)
  freq[which.max(tabulate(match(data, freq)))]
}

data <- diamonds %>% 
        mutate(across(where(is.numeric), ~ replace_na(., median(., na.rm = TRUE)))) %>% 
        mutate(across(where(is.numeric), scale))  %>%
        mutate(across(where(negate(is.numeric)), ~ replace_na(.x, mode(.x)))) 

model <- lm(price~., data=data)

model <- step(model)
summary(model)
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Call:
lm(formula = price ~ carat + cut + color + clarity + depth + 
    table + x + z, data = data)

Residuals:
    Min      1Q  Median      3Q     Max 
-5.3588 -0.1485 -0.0460  0.0943  2.6806 

Coefficients:
             Estimate Std. Error  t value Pr(>|t|)    
(Intercept) -0.140019   0.002461  -56.892  < 2e-16 ***
carat        1.337607   0.005775  231.630  < 2e-16 ***
cut.L        0.146537   0.005634   26.010  < 2e-16 ***
cut.Q       -0.075753   0.004508  -16.805  < 2e-16 ***
cut.C        0.037210   0.003876    9.601  < 2e-16 ***
cut^4       -0.005168   0.003101   -1.667  0.09559 .  
color.L     -0.489337   0.004347 -112.572  < 2e-16 ***
color.Q     -0.168463   0.003955  -42.599  < 2e-16 ***
color.C     -0.041429   0.003691  -11.224  < 2e-16 ***
color^4      0.009574   0.003391    2.824  0.00475 ** 
color^5     -0.024008   0.003202   -7.497 6.64e-14 ***
color^6     -0.012145   0.002911   -4.172 3.02e-05 ***
clarity.L    1.027115   0.007584  135.431  < 2e-16 ***
clarity.Q   -0.482557   0.007075  -68.205  < 2e-16 ***
clarity.C    0.246230   0.006054   40.676  < 2e-16 ***
clarity^4   -0.091485   0.004834  -18.926  < 2e-16 ***
clarity^5    0.058563   0.003948   14.833  < 2e-16 ***
clarity^6    0.001722   0.003438    0.501  0.61640    
clarity^7    0.022716   0.003034    7.487 7.13e-14 ***
depth       -0.022984   0.001622  -14.168  < 2e-16 ***
table       -0.014843   0.001631   -9.103  < 2e-16 ***
x           -0.281282   0.008097  -34.740  < 2e-16 ***
z           -0.008478   0.005872   -1.444  0.14880    
---
Signif. codes:  0***' 0.001 ‘**' 0.01*' 0.05 ‘.' 0.1' 1

Residual standard error: 0.2833 on 53917 degrees of freedom
Multiple R-squared:  0.9198,    Adjusted R-squared:  0.9198 
F-statistic: 2.81e+04 on 22 and 53917 DF,  p-value: < 2.2e-16

R’s syntactic sugar makes this linear equation remarkably simple to both code and comprehend. Now, let’s shift our focus to where Python reigns supreme.

Python: The Machine Learning Powerhouse

Python, a versatile general-purpose language, boasts a prominent user community dedicated to machine learning, leveraging popular libraries like scikit-learn, imbalanced-learn, and Optuna. Many influential machine learning toolkits, including TensorFlow, PyTorch, and Jax, are primarily designed for Python.

Python’s syntactic sugar is particularly appealing to machine learning practitioners. This includes its concise data pipeline syntax and scikit-learn’s fit-transform-predict pattern:

  1. Transform data to make it suitable for the model.
  2. Construct a model (implicitly or explicitly).
  3. Fit the model to the data.
  4. Make predictions on new data (supervised model) or transform the data (unsupervised model).
    • For supervised models, calculate an error metric for the new data points.

The scikit-learn library elegantly encapsulates this pattern while simplifying programming for exploration and visualization. It also offers numerous features for each stage of the machine learning cycle, including cross-validation, hyperparameter tuning, and pipelines.

A Diamond Machine Learning Model with Python

Let’s delve into a simple machine learning example using Python, one without a direct equivalent in R. We’ll employ the same dataset and highlight the fit-transform-predict pattern in a concise code snippet.

Adhering to a machine learning approach, we’ll partition our data into training and testing sets. We’ll apply identical transformations to both partitions and streamline the operations using a pipeline. The fit and score methods exemplify the potent machine learning capabilities within scikit-learn:

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import numpy as np
import pandas as pd
from sklearn.linear_model LinearRegression
from sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler
from sklearn.preprocessing import OneHotEncoder
from sklearn.impute import SimpleImputer
from sklearn.pipeline import Pipeline
from sklearn.compose import ColumnTransformer
from pandas.api.types import is_numeric_dtype

diamonds = sns.load_dataset('diamonds')
diamonds = diamonds.dropna()

x_train,x_test,y_train,y_test = train_test_split(diamonds.drop("price", axis=1), diamonds["price"], test_size=0.2, random_state=0)

num_idx = x_train.apply(lambda x: is_numeric_dtype(x)).values
num_cols = x_train.columns[num_idx].values
cat_cols = x_train.columns[~num_idx].values

num_pipeline = Pipeline(steps=[("imputer", SimpleImputer(strategy="median")), ("scaler", StandardScaler())])
cat_steps = Pipeline(steps=[("imputer", SimpleImputer(strategy="constant", fill_value="missing")), ("onehot", OneHotEncoder(drop="first", sparse=False))])

# data transformation and model constructor
preprocessor = ColumnTransformer(transformers=[("num", num_pipeline, num_cols), ("cat", cat_steps, cat_cols)])

mod = Pipeline(steps=[("preprocessor", preprocessor), ("linear", LinearRegression())])

# .fit() calls .fit_transform() in turn
mod.fit(x_train, y_train)

# .predict() calls .transform() in turn
mod.predict(x_test)

print(f"R squared score: {mod.score(x_test, y_test):.3f}")

This demonstrates the streamlined nature of the machine learning process in Python. Furthermore, Python’s sklearn classes help developers prevent data leakage and other issues related to data flow through the model, all while generating structured, production-ready code.

Beyond Statistics and Machine Learning: Further Capabilities of R and Python

In addition to statistical applications and machine learning model creation, R and Python excel in reporting, APIs, interactive dashboards, and seamless integration of external low-level code libraries.

While both R and Python enable the generation of interactive reports, R makes the process significantly simpler. Additionally, R supports exporting these reports to PDF and HTML formats.

Both languages empower data scientists to build interactive data applications. R utilizes the Shiny library, while Python leverages Streamlit for this purpose.

Lastly, both R and Python support external bindings to low-level code. This is commonly employed to inject high-performance operations into a library, making them callable from within the chosen language. R utilizes the Rcpp package for this purpose, while Python employs the pybind11 package.

Python and R: Increasingly Refined

In my data science work, I regularly use both R and Python. The key is to discern each language’s strengths and tailor the problem to fit an elegant coding solution.

When communicating with clients, data scientists aim for clarity. Therefore, we must carefully consider whether a statistical or machine learning presentation is more effective and select the most appropriate language accordingly.

Both Python and R offer a constantly expanding array of syntactic sugar, simplifying our work as data scientists and enhancing its comprehensibility to others. The more refined our syntax, the easier it becomes to automate and interact with our preferred languages. I appreciate the elegance that “sweet” data science languages provide, and the elegant solutions they produce are even sweeter.

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