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Python Language Basics - 2


Slice string in python:

details= "Akshay Kumar Gupta--akshaygupta.me"

# details[:6] and details[0:6] will give same result
print(details[:6]) # OUTPUT: Akshay

# details[20:] and details[20:34] will give same result
print(details[20:]) # OUTPUT: akshaygupta.me

# -1 denotes the reverse order
print(details[11::-1]) #OUTPUT: ramuK yahskA

# Here -9 denotes the count from the end of the string
print(details[:-9:-1]) #OUTPUT: em.atpug

#Both syntax gives the same result for reversing the string
print(details[-1::-1]) #OUTPUT: em.atpugyahska--atpuG ramuK yahskA
print(details[::-1]) #OUTPUT: em.atpugyahska--atpuG ramuK yahskA


Format print in python:

print("hi, My name is {} and I am a {}. I like {}."
.format("Akshay", "Software Engineer", "python"))

  • In the above print statement, "{}" refers to the placement of the values given in "format()" function.
  • First value in the order "format()" function will replace the first "{}" in the given string and so on.
print("hi, I am studying {0} language. It is easy to understand. {0} is generally used in {1}."
.format("python", "data science"))
  • In above example index number is defined inside the "{}" that refers to the position of the values in "format()" function.
  • "{0}" refers to the "python" and used two times in the string.
print("I got {0:15}% in my exam that is approx {0:5.1f}%. {1:10} was tough but I passed."
.format(69.967789, "math test"))
  • {0:15} refers to the {<position> : <spaces before the value in string>}
  • {0:5.1f} refers to the {<position> : <spaces before the value in string>.<round off value in float>f}
  • "1f" means value will be round off to one digit after the decimal.
  • Out of theh above print statement will be:
hi, I am studying python language. It is easy to understand. python is generally used in data science.. I got 69.967789% in my exam that is approx 70.0%. math test was tough but I passed.


f-string in python:
marks = 69.967789
print(f"I got {marks}% in my exam that is approx {marks:5.1f}%.")
  • Put letter "f" before writing the string.
  • Use the {} and put the value in it.
  • It follows the below formatting inside {}:
{<value>: <spaces before the value>.<round off to the given number for float values>f}
example: print(f"{69.967789:30.2f} is the my marks after round off two two digits")
> I got 69.97 marks after round off two two digits will give below output:

Sorting a list in Python:
# Sorting Numbers
numbers = [1, 4, 5, 3, 2]
# Immutable method for sorting
print(sorted(numbers))
# Mutable method for sorting
numbers.sort()
print(numbers)

# Sorting String
web_link = "AkshayGupta.Me"
# Immutable method for sorting
print(sorted(web_link))

# Case-Insensitive Sorting
# Immutable
countries = ["India", "USA", "Egypt", "UK"]
print(sorted(countries, key=str.casefold))
# Mutable
countries.sort(key=str.casefold)
print(countries)
Slice and replace the elements in list:
countries = ["India", "USA", "Egypt", "UK"]
countries[2:] = ["Russia", "Indonesia"]
print(countries) # ['India', 'USA', 'Russia', 'Indonesia']
Delete elements from list in python:
countries = ["India", "USA", "Egypt", "UK"]
# delete multiple countries
del countries[2:] # ['India', 'USA']
# delete single country
del countries[1] # ['India', 'Egypt', 'UK']

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