Book Image

Python for Finance

By : Yuxing Yan
Book Image

Python for Finance

By: Yuxing Yan

Overview of this book

Table of Contents (20 chapters)
Python for Finance
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Logic relationships related to an array


An array could contain true and false as shown in the following lines of code. This data type is called Boolean.

>>>import numpy as np
>>>x=np.array([True,Talse,True,False],bool)
>>>a=any(x)  	# if one item is TRUE then return TRUE
>>>b=all(x)  	# if all are TRUE then return TRUE
>>>cashFlows=np.array([-100,50,40,30,100,-5])
>>>a=cashFlows>0  # [False,True,True,True,True,False]
>>>np.logical_and(cashFlows>0, cashFlows<60)
Array([False,True,True,False,False],dtype=bool)

The logical_and(), logical_or(), and logical_not() functions could be used to compare each data item included in an array as shown in the previous code example. In addition, we could save the index or subscripts of the logic comparison and call the array later as shown in the following lines of code:

>>>cashFlows=np.array([-100,50,40,30,100,-5])
>>>index=(cashFlows>0) # index is a Boolean variable...