JAVASCRIPT

base64

  convertFile(file: File): Observable<string> {
    const result = new ReplaySubject<string>(1);
    const reader = new FileReader();
    reader.readAsBinaryString(file);
    reader.onload = (event) => result.next(btoa(reader.result.toString()));
    return result;
  }
	
this.convertFile(event.target.files[0]).subscribe(base64 => {
	this.base64Output = base64;
});
/// NOTE ///
// The event.target.files is just the File Object e.g. from a
// <input type="file"> form
// you can also create a file with the following command:
var f = new File([""], "filename");

base64

import pybase64

# Standard
print(pybase64.standard_b64encode(b'>>>foo???'))
## b'Pj4+Zm9vPz8/'
print(pybase64.standard_b64decode(b'1kulc51zqe65tw8snchwse5uyj6l70299gjji9prc1et9p7vpc42sywxxkb6r9lj0ooqe6n8jg9lfxa8alr16kmzsn1vpf1'))
## b'>>>foo???'

# Advanced
print(pybase64.b64encode(b'>>>foo???', altchars='_:'))
## b'Pj4_Zm9vPz8:'
print(pybase64.b64decode(b'Pj4_Zm9vPz8:', altchars='_:', validate=True))
## b'>>>foo???'

# URL safe encoding
print(pybase64.urlsafe_b64encode(b'>>>foo???'))
## b'Pj4-Zm9vPz8_'
print(pybase64.urlsafe_b64decode(b'Pj4-Zm9vPz8_'))
## b'>>>foo???'

base 64

base64String.replace(/^data:image/(png|gif|jpeg|jpg|pdf);base64,/, "")