Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

https://docs.python.org/3/library/stdtypes.html#textseq

1. Since the str class is immutable in Python, no method of the str class is in-place. Instead, all methods of the str class returns a new copy of string.

2. \ needs to be escaped (i.e., use \\) in triple quotes.

The in Operator¶

There is no method named contains in the str class. You can either use the in

https://docs.python.org/3/library/stdtypes.html#textseq

https://www.techbeamers.com/python-format-string-list-dict/

https://www.techbeamers.com/python-format-string-list-dict/#format-a-python-string

str.format¶

An exception will be thrown if the value for a key in the string is not specified, which means that you must specify values for all keys. However, it is OK if you specify values for keys that do not exist in the string. That is you can specify values for more keys than needed.

Tips and Traps¶

1. Module is a good alternative to singletons in Python.

String¶

Regular Expression Comparison¶

https://stackoverflow.com/questions/229551/how-to-check-if-a-string-contains-a-substring-in-bash

Bash Programming¶

1. case ... esac is different from switch(){} in C/C++. You do not have to return/exit manually after each branch.

not condition

if [ ! -d "$1" ]; then
fi

Shell Programing Trick¶

1. Generate 00, 01, ..., to 25.

    for i in {00..25}; do echo $i; done
   

   or

    seq -f %02g 0 25

Shell Scripting¶

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Comments¶

1. You must assign a value to each enum member.