Can You Make Multiple "If" Conditions in Python

How to have multiple conditions for one if statement in python

I would use

def example(arg1, arg2, arg3):
     if arg1 == 1 and arg2 == 2 and arg3 == 3:
          print("Example Text")

The and operator is identical to the logic gate with the same name; it will return 1 if and only if all of the inputs are 1. You can also use or operator if you want that logic gate.

EDIT: Actually, the code provided in your post works fine with me. I don't see any problems with that. I think that this might be a problem with your Python, not the actual language.

Can you make multiple if conditions in Python?

Python indeed allows you to do such a thing

if integer > 3 and integer < 34

Python is also smart enough to handle:

if 3 < integer < 34:
    # do your stuff

Styling multi-line conditions in 'if' statements?

You don't need to use 4 spaces on your second conditional line. Maybe use:

if (cond1 == 'val1' and cond2 == 'val2' and 
       cond3 == 'val3' and cond4 == 'val4'):
    do_something

Also, don't forget the whitespace is more flexible than you might think:

if (   
       cond1 == 'val1' and cond2 == 'val2' and 
       cond3 == 'val3' and cond4 == 'val4'
   ):
    do_something
if    (cond1 == 'val1' and cond2 == 'val2' and 
       cond3 == 'val3' and cond4 == 'val4'):
    do_something

Both of those are fairly ugly though.

Maybe lose the brackets (the Style Guide discourages this though)?

if cond1 == 'val1' and cond2 == 'val2' and \
   cond3 == 'val3' and cond4 == 'val4':
    do_something

This at least gives you some differentiation.

Or even:

if cond1 == 'val1' and cond2 == 'val2' and \
                       cond3 == 'val3' and \
                       cond4 == 'val4':
    do_something

I think I prefer:

if cond1 == 'val1' and \
   cond2 == 'val2' and \
   cond3 == 'val3' and \
   cond4 == 'val4':
    do_something

Here's the Style Guide, which (since 2010) recommends using brackets.

Multiple IF statements in python

break doesn't let you leave if clauses, if that's what you are indeed attempting to break out of. The trick here is to remove the break statements and replace your second ifs with elifs like so:

if lineCount == 5:
    if line[0]:
        print line[0],'A5'
        OPfound = 1
    elif line[1]:
        print line[1],'B5'
        OPfound = 1
if lineCount == 4:
    if line[0]:
        print line[0],'A4'
        OPfound = 1
    elif line[1]:
        print line[1],'B4'
        OPfound = 1

This way you are only running through the second if statement in each lineCount clause if the first one failed, not every time.

Multiple if conditions, without nesting

I would write it like this, so the function ends once it encounters an error, and the most likely error should be on top, and if it encounters that error, it will return False and end the function. Else, it will check for all the other errors and then eventually conclude that the outcome is indeed True.

# testOutcome returns a boolean
outcome = testOutcome(a,b)

# Expects a and b
# Breaks out of the function call once error happens
def testOutcome(a,b):
    # Most likely error goes here
    if a != b:
        print("Error - 01")
        return False

    # Followed by second most likely error
    elif a["test_1"] != "test_value":
         print("Error - 02")
         return False

    # Followed by third most likely error
    elif "test_2" not in a:
         print("Error - 03")
         return False

    # Least likely Error
    elif a["test_3"] == "is long data string":
         print("Error - 04")
         return False

    else:
        return True

How to make a multiple if statements more pythonic and condensed?

Combine all the conditions into one:

good = type(USERNAME) == str and type(PASSWORD) == str and type(PHONE) == int AND type(CARRIER) == str and type(SERVER) == str

BTW, you generally shouldn't use int for phone numbers. Even though we call them phone numbers we don't perform any numeric operations on them. And putting a phone number in an int variable will lose leading zeroes.

multiple if else conditions in pandas dataframe and derive multiple columns

You need chained comparison using upper and lower bound

def flag_df(df):
    
    if (df['trigger1'] <= df['score'] < df['trigger2']) and (df['height'] < 8):
        return 'Red'
    elif (df['trigger2'] <= df['score'] < df['trigger3']) and (df['height'] < 8):
        return 'Yellow'
    elif (df['trigger3'] <= df['score']) and (df['height'] < 8):
        return 'Orange'
    elif (df['height'] > 8):
        return np.nan
    
df2['Flag'] = df2.apply(flag_df, axis = 1)

    student score   height  trigger1    trigger2    trigger3    Flag
0   A       100     7       84          99          114         Yellow
1   B       96      4       95          110         125         Red
2   C       80      9       15          30          45          NaN
3   D       105     5       78          93          108         Yellow
4   E       156     3       16          31          46          Orange

Note: You can do this with a very nested np.where but I prefer to apply a function for multiple if-else

Edit: answering @Cecilia's questions

1. what is the returned object is not strings but some calculations, for example, for the first condition, we want to return df['height']*2

Not sure what you tried but you can return a derived value instead of string using

def flag_df(df):

    if (df['trigger1'] <= df['score'] < df['trigger2']) and (df['height'] < 8):
        return df['height']*2
    elif (df['trigger2'] <= df['score'] < df['trigger3']) and (df['height'] < 8):
        return df['height']*3
    elif (df['trigger3'] <= df['score']) and (df['height'] < 8):
        return df['height']*4
    elif (df['height'] > 8):
        return np.nan

2. what if there are 'NaN' values in osome columns and I want to use df['xxx'] is None as a condition, the code seems like not working

Again not sure what code did you try but using pandas isnull would do the trick

def flag_df(df):

    if pd.isnull(df['height']):
        return df['height']
    elif (df['trigger1'] <= df['score'] < df['trigger2']) and (df['height'] < 8):
        return df['height']*2
    elif (df['trigger2'] <= df['score'] < df['trigger3']) and (df['height'] < 8):
        return df['height']*3
    elif (df['trigger3'] <= df['score']) and (df['height'] < 8):
        return df['height']*4
    elif (df['height'] > 8):
        return np.nan

One else for multiple if conditions

There are two ways to do this.

1). You can use one if statement, and and the conditions together. This will produce "short circuiting" behavior, in that it will continue through the functions until the first one fails, then none of the remaining will execute.

if function_1() and function_2() and function_3():
    print "Everythings went well"
else:
    Reboot

2) If you want all to execute, here is a method, though it is more cumbersome.:

successful = True

successful = successful and function_1()
successful = successful and function_2()
successful = successful and function_2()

if successful:
    print "Everythings went well"
else:
    Reboot

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