how to send string to python file and display it using terminal

Question

I want to know how can I get the string from terminal or command prompt and make lower case that string and display it on terminal or command prompt
I used this code but it's not working

// in main.py cmd or terminal

import sys
tdf = sys.argv[1]
print(tdf)

and in terminal

// in cmd or terminal

PS E:\Python\Project\At> python .\main.py "Hi"

when I used this in my terminal I got this error

File "C:\\Users\\miladm\\AppData\\Local\\Programs\\Python\\Python39\\lib\\encodings\\cp1256.py", line 19, in encode return codecs.charmap_encode(input,self.errors,encoding_table)[0] UnicodeEncodeError: 'charmap' codec can't encode character '\ی' in position 13: character maps to

Answer 1

Code:

import sys

print ("Data from terminal :",sys.argv)

while running the script use:

D:\python>python cmdline.py "hello"

Output:

Data from terminal : ['cmdline.py', 'hello']

Answer 2

run with python filename.py "arguments"

instead of

tdf = sys.argv[1]

Use,

tdf = sys.argv[-1]

because it will get the last argument on the command line. If no arguments are passed, it will be the script name itself, as sys.argv[0] is the name of the running program. in your case if there is no arguments passed it will create an error

import sys
tdf = sys.argv[-1]
print(tdf)

Answer 3

To read user input you can try the cmd module for easily creating a mini-command line interpreter (with help texts and autocompletion) and raw_input (input for Python 3+) for reading a line of text from the user.

text = raw_input("prompt")  # Python 2
text = input("prompt")  # Python 3

Command line inputs are in sys.argv. Try this in your script:

import sys
print (sys.argv)

There are two modules for parsing command line options: optparse (deprecated since Python 2.7, use argparse instead) and getopt. If you just want to input files to your script, behold the power of fileinput.