MATHEMATICA TUTORIAL

# Importing and Exporting Files

 Import["file","List"] import a one-dimensional list of data from a file Export["file",list,"List"] export list to a file as a one-dimensional list of data Import["file","Table"] import a two-dimensional table of data from a file Export["file",list,"Table"] export list to a file as a two-dimensional table of data Import["file","CSV"] import data in comma-separated format Export["file",list,"CSV"] export data in comma-separated format

Importing and exporting lists and tables of data.

This exports a list of data to the file .
 Out[1]=
Here are the contents of the file.
This imports the contents back into Mathematica.
 Out[3]=

If you want to use data purely within Mathematica, then the best way to keep it in a file is usually as a complete Mathematica expression, with all its structure preserved, as discussed in "Reading and Writing Mathematica Files: Files and Streams". But if you want to exchange data with other programs, it is often more convenient to have the data in a simple list or table format.

This exports a two-dimensional array of data.
 Out[4]=
When necessary, numbers are written in C or Fortran-like "E" notation.
This imports the array back into Mathematica.
 Out[6]=

If you have a file in which each line consists of a single number, then you can use Import["file", "List"] to import the contents of the file as a list of numbers. If each line consists of a sequence of numbers separated by tabs or spaces, then Import["file", "Table"] will yield a list of lists of numbers. If the file contains items that are not numbers, then these are returned as Mathematica strings.

This exports a mixture of textual and numerical data.
 Out[7]=
Here is the exported data.
This imports the data back into Mathematica.
 Out[9]=
With InputForm, you can explicitly see the strings.
 Out[10]//InputForm=
 Import["file","List"] treat each line as a separate numerical or other data item Import["file","Table"] treat each element on each line as a separate numerical or other data item Import["file","String"] treat the whole file as a single character string Import["file","Text"] treat the whole file as a single string of text Import["file",{"Text","Lines"}] treat each line as a string of text Import["file",{"Text","Words"}] treat each separated word as a string of text

Importing files in different formats.

This creates a file with two lines of text.
 Out[11]=
Here are the contents of the file.
This imports the whole file as a single string.
 Out[13]//InputForm=
This imports the file as a list of lines of text.
 Out[14]//InputForm=
This imports the file as a list of words separated by white space.
 Out[15]//InputForm=

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