What is the use of strip() funciton code example

Example 1: strip()

txt = ",,,,,rrttgg.....banana....rrr"
x = txt.strip(",.grt")
#outputs banana
print(x)

Example 2: python strip()

a = "  smurf   "

a = a.strip()
#remove space at begining and end of string
print(a)
#smurf