Python Cheatsheet

Return a copy of the string with its first character capitalized and the rest lowercased

Return centered in a string of length width. Padding is done using the specified fillchar (default is a space)

Return the number of non-overlapping occurrences of substring sub in the range [start, end]

Decodes the string using the codec registered for encoding

Return an encoded version of the string. Default encoding is the current default string encoding

Return True if the string ends with the specified suffix, otherwise return False

Return a copy of the string where all tab characters are replaced by one or more spaces, depending on the current column and the given tab size

Return the lowest index in the string where substring sub is found, such that sub is contained in the slice s[start:end]

Perform a string formatting operation

Like find(), but raise ValueError when the substring is not found

Return true if all characters in the string are alphanumeric and there is at least one character, false otherwise

Return true if all characters in the string are alphabetic and there is at least one character, false otherwise

Return true if all characters in the string are digits and there is at least one character, false otherwise

Return true if all cased characters in the string are lowercase and there is at least one cased character, false otherwise

Return true if there are only whitespace characters in the string and there is at least one character, false otherwise

Return true if the string is a titlecased string and there is at least one character, for example uppercase characters may only follow uncased characters and lowercase characters only cased ones

Return true if all cased characters in the string are uppercase and there is at least one cased character, false otherwise

Return a string which is the concatenation of the strings in the iterable iterable

Return the string left justified in a string of length width

Return a copy of the string converted to lowercase

Return a copy of the string with leading characters removed

Split the string at the first occurrence of sep, and return a 3-tuple containing the part before the separator, the separator itself, and the part after the separator

Return a copy of the string with all occurrences of substring old replaced by new

Return the highest index in the string where substring sub is found, such that sub is contained within s[start:end]

Like rfind() but raises ValueError when the substring sub is not found

Return the string right justified in a string of length width

Split the string at the last occurrence of sep, and return a 3-tuple containing the part before the separator, the separator itself, and the part after the separator

Return a list of the words in the string, using sep as the delimiter string

Return a copy of the string with trailing characters removed

Return a list of the words in the string, using sep as the delimiter string

Return a list of the lines in the string, breaking at line boundaries

Return True if string starts with the prefix, otherwise return False

Return a copy of the string with the leading and trailing characters removed

Return a copy of the string with uppercase characters converted to lowercase and vice versa

Return a titlecased version of the string where words start with an uppercase character and the remaining characters are lowercase

Return a copy of the string where all characters occurring in the optional argument deletechars are removed, and the remaining characters have been mapped through the given translation table, which must be a string of length 256

Return a copy of the string converted to uppercase

Return the numeric string left filled with zeros in a string of length width

Return True if there are only numeric characters in S, False otherwise. Numeric characters include digit characters, and all characters that have the Unicode numeric value property, e.g. U+2155, VULGAR FRACTION ONE FIFTH

Return True if there are only decimal characters in S, False otherwise

Initialize the basic random number generator

Return an object capturing the current internal state of the generator

State should have been obtained from a previous call to getstate(), and setstate() restores the internal state of the generator to what it was at the time setstate() was called

Change the internal state to one different from and likely far away from the current state

Returns a python long int with k random bits

Return a randomly selected element from range(start, stop, step)

Return a random integer N such that a <= N <= b

Return a random element from the non-empty sequence seq

Shuffle the sequence x in place

Return a k length list of unique elements chosen from the population sequence

Return the next random floating point number in the range [0.0, 1.0)

Return a random floating point number N such that a <= N <= b for a <= b and b <= N <= a for b < a

Return a random floating point number N such that low <= N <= high and with the specified mode between those bounds

Beta distribution

Exponential distribution

Gamma distribution

Gaussian distribution

Log normal distribution

Normal distribution

Mu is the mean angle, expressed in radians between 0 and 2*pi, and kappa is the concentration parameter, which must be greater than or equal to zero

Pareto distribution

Weibull distribution

Return the ceiling of x as a float, the smallest integer value greater than or equal to x

Return x with the sign of y

Return the absolute value of x

Return x factorial

Return the floor of x as a float, the largest integer value less than or equal to x

Return fmod(x, y), as defined by the platform C library

Return the mantissa and exponent of x as the pair (m, e)

Return an accurate floating point sum of values in the iterable

Check if the float x is positive or negative infinity

Check if the float x is a NaN (not a number)

Return x * (2**i)

Return the fractional and integer parts of x

Return the Real value x truncated to an Integral (usually a long integer)

Return e**x

With one argument, return the natural logarithm of x (to base e)

Return the natural logarithm of 1+x (base e)

Return the base-10 logarithm of x

Return x raised to the power y

Return the square root of x

Return the arc cosine of x, in radians

Return the arc sine of x, in radians

Return the arc tangent of x, in radians

Return atan(y / x), in radians

Return the cosine of x radians

Return the Euclidean norm, sqrt(x*x + y*y)

Return the sine of x radians

Return the tangent of x radians

Converts angle x from radians to degrees

Converts angle x from degrees to radians

Return the inverse hyperbolic cosine of x

Return the inverse hyperbolic sine of x

Return the inverse hyperbolic tangent of x

Return the hyperbolic cosine of x

Return the hyperbolic sine of x

Return the hyperbolic tangent of x

Close the file

Flush the internal buffer, like stdio‘s fflush()

Return the integer “file descriptor” that is used by the underlying implementation to request I/O operations from the operating system

Return True if the file is connected to a tty(-like) device, else False

A file object is its own iterator, for example iter(f) returns f (unless f is closed)

Read at most size bytes from the file (less if the read hits EOF before obtaining size bytes)

Read one entire line from the file

Read until EOF using readline() and return a list containing the lines thus read

This method returns the same thing as iter(f)

Set the file’s current position, like stdio‘s fseek()

Return the file’s current position, like stdio‘s ftell()

Truncate the file’s size

Write a string to the file

Write a sequence of strings to the file

Bool indicating the current state of the file object

The encoding that this file uses

The Unicode error handler used along with the encoding

The I/O mode for the file

If the file object was created using open(), the name of the file

If Python was built with the --with-universal-newlines option to configure (the default) this read-only attribute exists, and for files opened in universal newline read mode it keeps track of the types of newlines encountered while reading the file

Boolean that indicates whether a space character needs to be printed before another value when using the print statement

Append a new item with value x to the end of the array

Return a tuple (address, length) giving the current memory address and the length in elements of the buffer used to hold array’s contents

“Byteswap” all items of the array

Return the number of occurrences of x in the array

Append items from iterable to the end of the array

Read n items (as machine values) from the file object f and append them to the end of the array

Append items from the list

Appends items from the string, interpreting the string as an array of machine values (as if it had been read from a file using the fromfile() method)

Extends this array with data from the given unicode string

Return the smallest i such that i is the index of the first occurrence of x in the array

Insert a new item with value x in the array before position i

Removes the item with the index i from the array and returns it

Remove the first occurrence of x from the array

Reverse the order of the items in the array

Write all items (as machine values) to the file object f

Convert the array to an ordinary list with the same items

Convert the array to an array of machine values and return the string representation (the same sequence of bytes that would be written to a file by the tofile() method.)

Convert the array to a unicode string

Return True if the set has no elements in common with other

Test whether every element in the set is in others

Test whether every element in other is in the set

Return a new set with elements from the set and all others

Return a new set with elements common to the set and all others

Return a new set with elements in the set that are not in the others

Return a new set with elements in either the set or other but not both

Return a new set with a shallow copy of s

Update the set, adding elements from all others

Update the set, adding elements from all others

Update the set, removing elements found in others

Update the set, keeping only elements found in either set, but not in both

Add element elem to the set

Remove element elem from the set. Raises KeyError if elem is not contained in the set

Remove element elem from the set if it is present

Remove element elem from the set if it is present

Remove all elements from the set

Remove all items from the dictionary

Return a shallow copy of the dictionary

Create a new dictionary with keys from seq and values set to value

Return the value for key if key is in the dictionary, else default

Test for the presence of key in the dictionary. has_key() is deprecated in favor of key in d

Return a copy of the dictionary’s list of (key, value) pairs

Return an iterator over the dictionary’s (key, value) pairs. See the note for dict.items()

Return an iterator over the dictionary’s keys. See the note for dict.items()

Return an iterator over the dictionary’s values. See the note for dict.items()

Return a copy of the dictionary’s list of keys. See the note for dict.items()

If key is in the dictionary, remove it and return its value, else return default

Remove and return an arbitrary (key, value) pair from the dictionary

If key is in the dictionary, return its value. If not, insert key with a value of default and return default

Update the dictionary with the key/value pairs from other, overwriting existing keys. Return None

Return a copy of the dictionary’s list of values. See the note for dict.items()