using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"\s*
(?:
(?:^from\s+
( # Base (from (base) import ...)
(?:[a-zA-Z_][a-zA-Z_0-9]* # Variable name
(?:\.[a-zA-Z_][a-zA-Z_0-9]*)* # Attribute (.attr)
)
)\s+import\s+
)
|
(?:^import\s|,)\s*
)
( # Name of imported module (import (this))
(?:[a-zA-Z_][a-zA-Z_0-9]* # Variable name
(?:\.[a-zA-Z_][a-zA-Z_0-9]*)* # Attribute (.attr)
)
)
(?:
\s+as\s+
( # Variable module is imported into (import foo as bar)
(?:[a-zA-Z_][a-zA-Z_0-9]* # Variable name
(?:\.[a-zA-Z_][a-zA-Z_0-9]*)* # Attribute (.attr)
)
)
)?
\s*
(?=,|$) # Ensure there is another thing being imported or it is the end of string";
string input = @"import pandas, os, sys";
RegexOptions options = RegexOptions.Multiline | RegexOptions.IgnorePatternWhitespace;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx