Search results
Anatomy of a Function def main(): mid = average(10.6, 7.2) print(mid) def average(a, b): sum = a + b return sum / 2 Think/Pair/Share: Find the function definition, function name, parameter(s), and return value in average.
- 1MB
- 116
This document is a selflearning document for a course in Python programming. This course contains (1) a part for beginners, (2) a discussion of several advanced topics that are of interest to Python programmers, and (3) a Python workbook with
- 1MB
- 278
- Index
- WHETTING YOUR APPETITE
- 2.2.1 Error Handling
- 2.2.2 Executable Python Scripts
- 2.2.4 The Interactive Startup File
- import os
- 2.2.5 The Customization Modules
- AN INFORMAL INTRODUCTION TO PYTHON
- 3.1 Using Python as a Calculator
- 3.1.2 Strings
- ’"Yes," he said.’
- ’"Isn\’t," she said.’
- "Isn’t," she said.
- ’First line.\nSecond line.’
- First line. Second line.
- C:\some\name
- Usage: thingy [OPTIONS] -h -H hostname """) Display this usage message Hostname to connect to
- ’Python’
- ’Pypy’
- MORE CONTROL FLOW TOOLS
- 4.1 if Statements
- More
119 Python is an easy to learn, powerful programming language. It has efficient high-level data structures and a simple but effective approach to object-oriented programming. Python’s elegant syntax and dynamic typing, together with its interpreted nature, make it an ideal language for scripting and rapid application development in many areas on mo...
If you do much work on computers, eventually you find that there’s some task you’d like to automate. For example, you may wish to perform a search-and-replace over a large number of text files, or rename and rearrange a bunch of photo files in a complicated way. Perhaps you’d like to write a small custom database, or a specialized GUI application, ...
When an error occurs, the interpreter prints an error message and a stack trace. In interactive mode, it then returns to the primary prompt; when input came from a file, it exits with a nonzero exit status after printing the stack trace. (Exceptions handled by an except clause in a try statement are not errors in this context.) Some errors are unco...
On BSD’ish Unix systems, Python scripts can be made directly executable, like shell scripts, by putting the line #! /usr/bin/env python3.3 (assuming that the interpreter is on the user’s PATH) at the beginning of the script and giving the file an executable mode. The #! must be the first two characters of the file. On some platforms, this first lin...
When you use Python interactively, it is frequently handy to have some standard commands executed every time the interpreter is started. You can do this by setting an environment variable named PYTHONSTARTUP to the name of a file containing your start-up commands. This is similar to the .profile feature of the Unix shells. This file is only read in...
filename = os.environ.get(’PYTHONSTARTUP’) if filename and os.path.isfile(filename): exec(open(filename).read())
Python provides two hooks to let you customize it: sitecustomize and usercustomize. To see how it works, you need first to find the location of your user site-packages directory. Start Python and run this code: >> import site >> site.getusersitepackages() ’/home/user/.local/lib/python3.2/site-packages’ Now you can create a file named usercustomize....
In the following examples, input and output are distinguished by the presence or absence of prompts (>>> and ...): to repeat the example, you must type everything after the prompt, when the prompt appears; lines that do not begin with a prompt are output from the interpreter. Note that a secondary prompt on a line by itself in an example means you ...
Let’s try some simple Python commands. Start the interpreter and wait for the primary prompt, >>>. (It shouldn’t take long.)
Besides numbers, Python can also manipulate strings, which can be expressed in several ways. They can be enclosed in single quotes (’...’) or double quotes ("...") with the same result 2. \ can be used to escape quotes: > ’spam eggs’ # single quotes ’spam eggs’ > ’doesn\’t’ # use \’ to escape the single quote... "doesn’t" > "doesn’t" # ...or use do...
> "\"Yes,\" he said." ’"Yes," he said.’ > ’"Isn\’t," she said.’
In the interactive interpreter, the output string is enclosed in quotes and special characters are escaped with back-slashes. While this might sometimes look different from the input (the enclosing quotes could change), the two strings are equivalent. The string is enclosed in double quotes if the string contains a single quote and no double quotes...
>> s = ’First line.\nSecond line.’ # \n means newline >> s # without print(), \n is included in the output
> print(s) # with print(), \n produces a new line
If you don’t want characters prefaced by \ to be interpreted as special characters, you can use raw strings by adding an r before the first quote: > print(’C:\some\name’)
# here \n means newline! # note the r before the quote String literals can span multiple lines. One way is using triple-quotes: """...""" or ”’...”’. End of lines are automatically included in the string, but it’s possible to prevent this by adding a \ at the end of the line. The following example: print("""\
produces the following output (note that the initial newline is not included):
This only works with two literals though, not with variables or expressions: >> prefix = ’Py’ >> prefix ’thon’ # can’t concatenate a variable and a string literal ...
The built-in function len() returns the length of a string: >> s = ’supercalifragilisticexpialidocious’ >> len(s) 34 See Also: textseq Strings are examples of sequence types, and support the common operations supported by such types. string-methods Strings support a large number of methods for basic transformations and searching. string-formatting ...
Besides the while statement just introduced, Python knows the usual control flow statements known from other languages, with some twists.
Perhaps the most well-known statement type is the if statement. For example: > x = int(input("Please enter an integer: "))
There can be zero or more elif parts, and the else part is optional. The keyword ‘elif‘ is short for ‘else if’, and is useful to avoid excessive indentation. An if ... elif ... elif ... sequence is a substitute for the switch or case statements found in other languages.
- 635KB
- 127
A function is a group of statements that exist within a program for the purpose of performing a specific task. Since the beginning of the semester we have been using a number of Python’s built-in functions, including: print() range() len() random.randint() ... etc.
- 1MB
- 85
Defining Functions in Python Overview: This activity focuses on an important idea in programming: user-defined functions. This concept appears in practically every programming language, and in Python, there are some particular options available (default arguments, for example) that make it easy to define functions in flexible ways. Motivation:
FUNCTIONS. A function = a value that contains code (a sequence of statements). Is usually stored in a variable. def variable(): Statement 1. Syntax: Statement 2 Statement ... Statements in the function are executed when the function is called. The call expression: <expr> ()
People also ask
What is a function in Python?
What does F5 mean in Python?
How to implement an interface in Python?
This Introduction is a sample to Python from “Python 3” Basics: A Practical. With to the go the full version of the book you all the is explained way from and beginner get a complete Python curriculum illustrated to intermediate-level. with short & clear Every code step samples. along.
