Python für Dummies

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THE ZEN OF PYTHON VON TIM PETERS

Beautiful is better than ugly.

Explicit is better than implicit.

Simple is better than complex.

Complex is better than complicated.

Flat is better than nested.

Sparse is better than dense.

Readability counts.

Special cases aren't special enough to break the rules.

Although practicality beats purity.

Errors should never pass silently.

Unless explicitly silenced.

In the face of ambiguity, refuse the temptation to guess.

There should be one - and preferably only one - obvious way to do it.

Although that way may not be obvious at first unless you're Dutch.

Now is better than never.

Although never is often better than *right* now.

If the implementation is hard to explain, it's a bad idea.

If the implementation is easy to explain, it may be a good idea.

Namespaces are one honking great idea - let's do more of those!

COMPREHENSIONS

Liste

[i for i in iterable]

Set

{i for i in iterable}

Dictionary

{key:value for key,value in iterable}

Generator Expression

(i for i in iterable)

CONTAINER

Liste

[1, 2, 3]

Tupel

(1, 2, 3)

Set

{1, 2, 3}

Dictionary

{'a': 1, 'b': 2 }

STRINGS

String

"Hello"

'Hello'

Mehrzeilig

"""Hello"""

'''Hello'''

F-String

f'Hello, {variable}'

Bytes

b'Hello'

Raw

r'Hello'

RECHNEN

Grundrechenarten

6 + 3

12 - 3

3 * 3

18 / 2

Division ohne Rest

19 // 2

Modulo

19 % 10

Potenzieren

3 ** 2

LOGIK

Boolean

True, False

Und

True and True

Oder

True or False

Negation

not False

ZAHLENLITERALE

Floats

-39.23

Wissenschaftlich

1.90e-3

Integer

23

Mit Trennzeichen

10_000_000

Binär

0b1100110011

Oktal

0o123

Hexadezimal

0xff00ff

VERGLEICHEN

Identität

a is a

Inklusion

'a' in 'abc'

Vergleiche

3 == 3

1 != 2

1 < 2

2 > 1

2 <= 2

2 >= 2

FORMATIERUNG: STRINGS

Linksbündig

f'{pi:<10.4f}'

'3.1416 '

Zentriert

f'{pi:^10.4f}'

' 3.1416 '

Rechtsbündig

f'{pi:>10.4f}'

' 3.1416'

Zeichen auffüllen

f'{.5: ^10.2%}'

'~ 50.00%  '

Runden

f'{12.5865:.3f}'

'12.586'

Wissenschaftlich

f'{pi:E}'

'3.141593E+00'

Prozent

f'{.5:.2%}'

'50.00%'

Maskieren

f'{iban:*<22.8}'

'DE893704**************'

DATUMSFORMATE

%d

Tag

%m

Monat

%Y / %y

Jahr vier-/zweistellig

%A / %a

Wochentag (lang/kurz)

%B / %b

Monatsname (lang/kurz)

%W

Kalenderwoche

%x

Komplettes Datum

ZEITFORMATE

%H / %I

Stunde (24/12)

%M

Minute

%S

Sekunde

%f

Mikrosekunde

%z

Zeitverschiebung (ab UTC)

%Z

Name der Zeitzone

%X

Komplette Zeit

Datum und Zeit Beispiele

Uhrzeit

now.strftime('%H:%M:%S.%f')

'17:23:20.011664'

Datum

now.strftime('%A, der %d. %B %Y')

'Montag, der 30. März 2020'

Falls nötig, Locale setzen:

import datetime, locale

locale.setlocale(locale.LC_ALL, 'de_de')

now =...