# ExternalEvaluate Usage

• ExternalEvaluate["Python",code] executes a code string in a Python REPL and returns the results as a Wolfram Language expression.
• ExternalEvaluate["Python""String",code] executes the code string in a Python REPL and does not interpret the results.

# Data Types

• Not all Python built-in types are supported. The supported Python types are:
•  bool True|False Boolean values bytearray ByteArray sequence of integers 0-255 bytes ByteArray immutable sequence of integers 0-255 complex Complex complex number date DateObject specific calendar date datetime DateObject specific date with time granularity Decimal Real arbitrary-precision real number dictionary Association association of keys and values float Real real-valued number Fraction Rational fraction object from the fractions module frozenset List unordered immutable set of unique values int Integer arbitrary-sized integer list List sequence of values long Integer arbitrary-sized integer None Null null value set List unordered set of unique values str String sequence of character values tuple List ordered sequence of values
• The precision of a Real returned from a Decimal object is maintained when returned from ExternalEvaluate.
• Python complex types are required to be real, and so any Complex expression returned from ExternalEvaluate will have real-valued components.

# Examples

## Basic Examples(1)

Evaluate in Python and return the result:

 In[1]:=
 Out[1]=

Create a list in Python and return the result:

 In[2]:=
 Out[2]=

Type > to get a Python code cell that uses ExternalEvaluate to evaluate:

import math [math.sqrt(i) for i in range(10)]
 Out[5]=

Create a list with exponentials and logarithms:

[[i,math.exp(i),math.log(i)] for i in range(1,10)]
 Out[11]=

Create a list with the days of the week:

import calendar [calendar.day_name[i] for i in range(7)]
 Out[8]=