one - python argparse check if argument exists - Code Examples My script is now working, but is a bit big (around 1200 lines). len (sys.argv) provides the number of command line arguments. # This can be useful for multiple things. Think simple! # # Add an argument that must be an existing file, but can also be specified as a dash ('-') in the command. Typically, this means sys.argv [1:]. Let us move to learn about argparse python. len (sys.argv) provides the number of command line arguments. python argparse check if argument exists - oki-kibihoujin.jp I ended up using BioPython to extract the sequences and then editing Ilya Steanov's implementation to remove the argparse methods. sys.argv [0] is the name of the current Python script. Python argparse check if argument exists python - Argparse: Check if any arguments have been passed Python