Python C859 WG: Q&A
Minimum field width with strings - ✔️ print('Student name (%5s)' %
'Bob'
the 5 specifies that there are a minimum of 5 characters and thus the print out
would be ( Bob)
Conversion flags - ✔️ alter the output of conversion specifiers
%08d adds leading zeros to the minimum width of 8 characters
precision components(Rounding) - ✔️ Indicates how many digits to
the right of the decimal should be included
'%.1f' % 1.725 indicates a precision of 1 resulting in 1.7
.replace() - ✔️ replace(old,new,count)
count replaces only the first occurrence
count can be left out
translation = translation.replace('one', 'uno')
.find(x) - ✔️ Returns the position of the first occurrence of item x in
the string
if my_str is 'Boo Hoo!'
my_str.find('!') Returns 7
my-str.find('Boo') Returns 0
my_str.find('oo') returns 1
find(x, start) - ✔️ Same as find(x) but begins the search at position
start
find(x, start, end) - ✔️ Same as find(x,start) but stops the search at
position end
rfind(x) - ✔️ Same as find but searches the string in reverse,
returning the last occurrence in the string
count(x) - ✔️ Returns the number of times x occurs in the string
,using in operator to check if a character or substring is contained in the string
- ✔️ if 'b' in my_string
Comparing Strings - ✔️ may be compared using relational operators
(<> <= etc..)
equality operators (==,!=)
membership operators (in,not in)
identity operators (is, is not)
my_str = 'Hello'
my_str == 'Hello" evaluates to True
relational comparison will compare the ASCII unicode values. if a string is
shorter with all the same characters then the shorter is considered less than
Do not use identity operators where you should be using an equality operator
comparisons are case sensitive
isalnum() - ✔️ Returns True if all characters int he string are
lowercase or uppercase letters, or the numbers 0-9
isdigit() - ✔️ Returns True if all characters are the numbers 0-9
islower() - ✔️ Returns True if all characters are lowercase letters
isupper() - ✔️ Returns True if all characters are uppercase letters
isspace() - ✔️ Returns True if all characters are whitespace
startswith(x) - ✔️ Returns True if the string starts with x
endswith(x) - ✔️ Returns True if the string ends with x
capitalize() - ✔️ Returns a copy of the string with the first character
capitalized and rest lowercased
lower() - ✔️ Returns a copy of the string with all characters
lowercased
, upper() - ✔️ Returns a copy of the string with all characters
uppercased
strip() - ✔️ Returns a copy of the string with leading and trailing
whitespace removed
can be used to turn a string literal into a list of items by using the whitespace
character as the default separator
if it was strip(/) the default separator would be the / character. If the string
contained a double // then an empty list element would be created
title() - ✔️ Returns a copy of the string with the first letters of words
capitalized
Good practice for input() data transformations - ✔️ apply the
transformations when reading in data as opposed to later in the program
join() - ✔️ Works in reverse to split()
It joins a list of strings together to create a single string
my_str = '@'.join(['billgates', 'microsoft']) binds the name my_str to a new
string object with the value 'billgates@microsoft'
each element from left to right is concatenated together.
The separator can be any string including multiple characters or an empty
string charater.
''.join will return the list as a string w/out separators.
string format method - ✔️ positional=
'The {1} in the {0}'.format('hat','cat') The cat in the hat
Inferred positional
'The {} in the {}'.format("cat",'hat') The cat in the hat
Named
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LeCrae. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.99. You're not tied to anything after your purchase.