SciPy - Input and Output

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SciPy is a Python library used for scientific and technical computing and it includes a range of input and output functions especially for handling various data formats.

The SciPy input and output (I/O) functions which enable reading and writing data in various scientific formats. The scipy.io module supports loading and saving MATLAB files with loadmat and savemat, reading and writing text files using NumPys loadtxt and savetxt and handling WAV audio files through wavfile.read and wavfile.write.

This also supports Fortran binary files and IDL .sav files with FortranFile and readsav. These I/O functions make SciPy versatile for data exchange across different formats commonly used in scientific computing and analysis.

Heres an overview of the main features and functions −

MATLAB Files (.mat files)

SciPy provides functionality for reading from and writing to MATLAB .mat files through the scipy.io module which is especially useful for users working with data in both Python and MATLAB. .mat files are binary files that store MATLAB variables and SciPys loadmat and savemat functions handle these files efficiently.

Here are the commonly used SciPy functions to use the .mat files −

S.No	Function	Description
1	scipy.io.loadmat	Reads .mat files and returns data in the form of a Python dictionary
2	scipy.io.savemat	Saves Python data structures (like dictionaries) to a .mat file.
3	scipy.io.whosmat	Lists the variables stored in a .mat file without loading the actual data.

Text and Binary File I/O

SciPy provides Functions for reading and writing data in text and binary formats such as .txt, .dat, and .csv files. These Functions rely on NumPys loadtxt, savetxt and genfromtxt methods.

• numpy.loadtxt: Loads data from a text file.
• numpy.savetxt: Saves an array to a text file.
• numpy.genfromtxt: Similar to loadtxt but allows for more flexible parsing such as handling missing values.

Wav Files

In SciPy WAV files can be read and written using Functions in the scipy.io.wavfile module which is ideal for simple audio data processing tasks. WAV files can contain multiple channels such as mono, stereo and various bit depths but SciPys Functions handle these with basic data type conversion.

Here are the SciPy Functions for handling the .wav files −

S.No.	Function	Description
1	scipy.io.wavfile.write	Writes data to a WAV file with a specified sample rate.
2	scipy.io.wavfile.read	Reads a WAV file and returns the sample rate in samples per second and the audio data as a NumPy array.

Fortran and IDL Files

Fortran and IDL files are types of data files commonly used in scientific computing especially in fields like physics, engineering and remote sensing. They originate from the programming languages Fortran and IDL (Interactive Data Language) respectively.

Fortran binary files can be read and written with the FortranFile class in scipy.io module. This class allows for low-level binary I/O in the format commonly used by Fortran programs.

SciPy also supports reading IDL .sav files which are used to store data in the IDL (Interactive Data Language) format. The scipy.io.readsav() Function reads IDL files and returns a dictionary with variable names as keys.

S.No.	Function	Description
1	scipy.io.FortranFile	Used for reading and writing binary data in Fortran.
2	scipy.io.readsav	Reads IDL .sav files into Python.

Image Files

In SciPy basic image file I/O is possible through the misc module and but for more advanced image processing libraries like imageio, PIL (Pillow) or OpenCV are often preferred. SciPys Functions allow basic reading and writing for formats like .png or .jpg.

S.No.	Function	Description
1	scipy.misc.face	Loads an image of a "face" that comes with the SciPy library for testing and demonstration purposes.